Phakathi kwama-oxide angewona ama-siliceous, i-alumina inezinto ezinhle zemishini, ukumelana nokushisa okuphezulu nokumelana nokugqwala, kuyilapho i-mesoporous alumina (MA) inosayizi we-pore oguquguqukayo, indawo enkulu ethize, umthamo omkhulu wembobo kanye nezindleko zokukhiqiza eziphansi, ezisetshenziswa kabanzi ku-catalysis, ukukhululwa kwezidakamizwa ezilawulwayo, i-adsorption kanye nezinye izinkambu, ezifana nokuqhekeka, i-hydrocracking kanye ne-hydrodesulfurization ye-petroleum raw materials.I-alumina encane ivame ukusetshenziswa embonini, kodwa izothinta ngokuqondile umsebenzi we-alumina, impilo yesevisi kanye nokukhetha kwe-catalyst.Isibonelo, ohlelweni lokuhlanzwa kwe-exhaust yezimoto, ukungcola okufakiwe okuvela ezithasiselweni zikawoyela wenjini kuzokwakha i-coke, okuzoholela ekuvinjweni kwama-catalyst pores, ngaleyo ndlela kunciphise umsebenzi we-catalyst.I-Surfactant ingasetshenziswa ukulungisa ukwakheka kwesithwali se-alumina ukuze yenze i-MA.Thuthukisa ukusebenza kwayo kwe-catalytic.
I-MA inomphumela ovimbelayo, futhi izinsimbi ezisebenzayo ziyavalwa ngemva kokubalwa kwezinga lokushisa eliphezulu.Ngaphezu kwalokho, ngemva kokubala izinga lokushisa eliphezulu, isakhiwo se-mesoporous siyawa, i-MA skeleton isesimweni se-amorphous, futhi i-asidi engaphezulu ayikwazi ukuhlangabezana nezidingo zayo emkhakheni wokusebenza.Ukwelashwa kokuguqulwa kuvame ukudingeka ukuze kuthuthukiswe umsebenzi we-catalytic, ukuqina kwesakhiwo se-mesoporous, ukuzinza kwe-thermal ebusweni kanye ne-acidity ebusweni bezinto ze-MA.Amaqembu okuguqula ajwayelekile ahlanganisa ama-heteroatom ensimbi (Fe, Co, Ni, Cu, Zn, Pd, Pt, Zr, njll. ) nama-oxide ensimbi (TiO2, NiO, Co3O4, CuO, Cu2O, RE2O7, njll.)Kulayishwe ebusweni be-MA noma kufakwe kuhlaka lwamathambo.
Ukucushwa kwe-electron okukhethekile kwezakhi zomhlaba ezingavamile kwenza izinhlanganisela zawo zibe nezindawo ezikhethekile zokubona, zikagesi kanye nezikazibuthe, futhi zisetshenziselwa izinto ze-catalytic, izinto ze-photoelectric, izinto ze-adsorption kanye nezinto kazibuthe.Izinto ze-mesoporous eziguquliwe ezingavamile zingalungisa impahla ye-asidi (alkali), zandise isikhala somoya-mpilo, futhi zihlanganise i-nanocrystalline catalyst yensimbi ngokuhlakazeka okufanayo kanye nesikali se-nanometer esizinzile.Izinto ezisetshenziswayo ezifanele kanye nomhlaba ongajwayelekile kungathuthukisa ukuhlakazwa komhlaba kwama-nanocrystals ensimbi nokuzinza kanye nokufakwa kwekhabhoni ukumelana nama-catalysts.Kuleli phepha, ukuguqulwa komhlaba okungavamile nokusebenza kwe-MA kuzokwethulwa ukuze kuthuthukiswe ukusebenza kwe-catalytic, ukuzinza kokushisa, umthamo wokugcina umoya-mpilo, indawo ethile yendawo kanye nesakhiwo se-pore.
1 MA ukulungiselela
1.1 ukulungiswa kwesithwali se-alumina
Indlela yokulungiselela isithwali se-alumina inquma ukusatshalaliswa kwesakhiwo se-pore, futhi izindlela zayo zokulungiselela ezivamile zihlanganisa indlela yokuphelelwa amanzi emzimbeni ye-pseudo-boehmite (PB) kanye nendlela ye-sol-gel.I-Pseudoboehmite (PB) yaqale yahlongozwa i-Calvet, futhi i-H+ yathuthukisa i-peptization ukuze ithole i-γ-AlOOH i-colloidal PB equkethe amanzi ahlanganayo, afakwa i-calcined futhi aphelelwa amanzi ezingeni lokushisa eliphezulu ukuze enze i-alumina.Ngokwezinto zokusetshenziswa ezihlukene, kuvame ukuhlukaniswa ngendlela yemvula, indlela ye-carbonization kanye nendlela ye-alcoloaluminium hydrolysis.I-colloidal solubility ye-PB ithintwa yi-crystallinity, futhi ithuthukiswa ngokunyuka kwe-crystallinity, futhi iphinde ithinteke imingcele yenqubo yokusebenza.
I-PB ivamise ukulungiswa ngendlela yemvula.I-alkali yengezwa esixazululweni se-aluminate noma i-asidi yengezwa esixazululweni se-aluminayithi bese iwa ukuze kutholwe i-alumina e-hydrated (imvula ye-alkali), noma i-asidi yengezwa emvuleni ye-aluminium ukuze kutholwe i-alumina monohydrate, esuke igezwe, yomiswe futhi ibalwe ukuze kutholwe i-PB.Indlela yemvula kulula ukuyisebenzisa futhi inezindleko eziphansi, evame ukusetshenziswa ekukhiqizeni izimboni, kodwa ithonywa izici eziningi (isixazululo se-pH, ukugxila, izinga lokushisa, njll.).Futhi leso simo sokuthola inhlayiya ene-dispersibility engcono siqinile.Ngendlela ye-carbonization, i-Al(OH)3 itholakala ngokusabela kwe-CO2 kanye ne-NaAlO2, futhi i-PB ingatholakala ngemva kokuguga.Le ndlela inezinzuzo zokusebenza okulula, ikhwalithi yomkhiqizo ophezulu, akukho ukungcola kanye nezindleko eziphansi, futhi ingalungisa i-alumina ngomsebenzi ophezulu we-catalytic, ukumelana nokugqwala okuhle kakhulu kanye nendawo ethile ephezulu ene-investimenti ephansi kanye nokubuya okuphezulu.Indlela ye-Aluminium alkoxide hydrolysis ivame ukusetshenziswa. ukulungisa i-PB enobumsulwa obukhulu.I-aluminium alkoxide i-hydrolyzed ukuze yakhe i-aluminium oxide monohydrate, bese iphathwa ukuze ithole ukuhlanzeka okuphezulu kwe-PB, ene-crystallinity enhle, usayizi wezinhlayiyana ezifanayo, ukusatshalaliswa kosayizi we-pore okugxilile kanye nobuqotho obuphezulu bezinhlayiya eziyindilinga.Kodwa-ke, le nqubo iyinkimbinkimbi, futhi kunzima ukululama ngenxa yokusetshenziswa kwezinyibilikisi ezithile ezinobuthi.
Ngaphezu kwalokho, usawoti wezinto ezingaphili noma izinhlanganisela eziphilayo zezinsimbi zivame ukusetshenziselwa ukulungiselela izanduleli ze-alumina nge-sol-gel indlela, futhi amanzi ahlanzekile noma izincibilikisi eziphilayo zengezwa ukuze kulungiswe izixazululo zokukhiqiza i-sol, esuke igeliswa, yomisiwe futhi yosiwe.Njengamanje, inqubo yokulungiselela i-alumina isathuthukisiwe ngesisekelo se-PB dehydration method, futhi indlela ye-carbonization isibe indlela eyinhloko yokukhiqiza i-alumina yezimboni ngenxa yomnotho wayo nokuvikelwa kwemvelo.I-Alumina elungiselelwe indlela ye-sol-gel iye yakhanga kakhulu. ngenxa yokusabalalisa usayizi wezimbotshana ezifanayo, okuyindlela engaba khona, kodwa idinga ukuthuthukiswa ukuze kufezeke ukusetshenziswa kwezimboni.
1.2 Ukulungiselela kwe-MA
I-alumina evamile ayikwazi ukuhlangabezana nezidingo zokusebenza, ngakho-ke kuyadingeka ukulungiselela i-MA esebenza kahle.Izindlela zokuhlanganisa ngokuvamile zihlanganisa: indlela ye-nano-casting ene-carbon mold njengesifanekiso esiqinile;Ukuhlanganiswa kwe-SDA: Inqubo yokuzihlanganisa ebangelwa ukuhwamuka (EISA) ebukhoneni bezifanekiso ezithambile ezifana ne-SDA namanye ama-cationic, anionic noma ama-nonionic surfactants.
1.2.1 Inqubo ye-EISA
Isifanekiso esithambile sisetshenziswa esimweni esine-asidi, esigwema inqubo eyinkimbinkimbi nedla isikhathi yendlela ye-membrane eqinile futhi ingabona ukuguquguquka okuqhubekayo kokuvula indawo.Ukulungiswa kwe-MA yi-EISA kudonse ukunaka okukhulu ngenxa yokutholakala kwayo kalula nokukhiqiza kabusha.Izakhiwo ezahlukene ze-mesoporous zingalungiswa.Ubukhulu bembotshana ye-MA bungalungiswa ngokushintsha ubude beketanga le-hydrophobic le-surfactant noma ukulungisa isilinganiso se-molar ye-hydrolysis catalyst kuya ku-aluminium isandulela kusixazululo.Ngakho-ke, i-EISA, eyaziwa nangokuthi i-synthesis yesinyathelo esisodwa kanye nokuguqulwa kwendlela ye-sol-gel yendawo ephezulu. indawo ye-MA kanye ne-odolo ye-mesoporous alumina (OMA), isetshenziswe ezifanekisweni ezithambile ezihlukahlukene, njenge-P123, F127, triethanolamine (itiye), njll. I-EISA ingathatha indawo yenqubo yokuhlanganiswa kwama-precursors e-organoaluminium, njengama-alkoxides e-aluminium kanye nezifanekiso ze-surfactant. , ngokuvamile i-aluminium isopropoxide ne-P123, yokuhlinzeka ngezinto ezibonakalayo ze-mesoporous.Ukuthuthukiswa okuyimpumelelo kwenqubo ye-EISA kudinga ukulungiswa okunembile kwe-hydrolysis kanye ne-condensation kinetics ukuze kutholwe i-sol ezinzile futhi kuvumele ukuthuthukiswa kwe-mesophase eyakhiwe ama-micelles aphuma ku-sol.
Enqubweni ye-EISA, ukusetshenziswa kwezinyibilikisi ezingenawo amanzi (njenge-ethanol) kanye nama-organic complexing agents kunganciphisa ngempumelelo izinga le-hydrolysis kanye ne-condensation lama-precursors e-organoaluminium futhi kubangele ukuzihlanganisa ngokwakho kwezinto ze-OMA, njenge-Al(OR)3and. aluminium isopropoxide.Kodwa-ke, kuzincibilikisi ezingenawo amanzi, izifanekiso ze-surfactant ngokuvamile zilahlekelwa yi-hydrophilicity/hydrophobicity yazo.Ngaphezu kwalokho, ngenxa yokubambezeleka kwe-hydrolysis kanye ne-polycondensation, umkhiqizo ophakathi nendawo uneqembu le-hydrophobic, okwenza kube nzima ukuxhumana nesifanekiso se-surfactant.Kuphela lapho ukugcwala kwe-surfactant kanye nezinga le-hydrolysis kanye ne-polycondensation ye-aluminium kukhula kancane kancane ohlelweni lokuhwamuka kwe-solvent lapho ukuzihlanganisa kwesifanekiso ne-aluminium kwenzeka.Ngakho-ke, amapharamitha amaningi athinta izimo zokuhwamuka kwezincibilikisi kanye nokusabela kwe-hydrolysis kanye nokujiya kwezandulela, Njengamazinga okushisa, umswakama ohlobene, i-catalyst, izinga lokuhwamuka kwe-solvent, njll., izothinta isakhiwo sokugcina somhlangano.Njengoba kuboniswe emkhiwaneni.1, izinto ze-OMA ezinokuzinza okuphezulu kokushisa nokusebenza okuphezulu kwe-catalytic zahlanganiswa ngokuzihlanganisa okubangelwa ukuhwamuka kwe-solvothermal (SA-EISA).ukwelashwa kwe-solvothermal kukhuthaze i-hydrolysis ephelele yezandulela ze-aluminium ukuze kwakhe amaqembu e-aluminium hydroxyl yeqoqo elincane, elithuthukise ukusebenzisana phakathi kwama-surfactants ne-aluminium.I-mesophase enezinhlangothi ezimbili enezinhlangothi ezimbili yakhiwa ngenqubo ye-EISA futhi yabalwa ku-400℃ ukuze yakhe impahla ye-OMA.Enqubweni yendabuko ye-EISA, inqubo yokuhwamuka ihambisana ne-hydrolysis ye-organoaluminium precursor, ngakho-ke izimo zokuhwamuka zinethonya elibalulekile ekuphenduleni kanye nesakhiwo sokugcina se-OMA.Isinyathelo sokwelashwa kwe-solvothermal sikhuthaza i-hydrolysis ephelele ye-aluminium precursor futhi ikhiqiza amaqembu e-aluminium hydroxyl ahlanganiswe kancane.OMA yakhiwe ngaphansi kwezimo eziningi zokuhwamuka.Uma kuqhathaniswa ne-MA elungiselelwe indlela ye-EISA yendabuko, i-OMA elungiselelwe indlela ye-SA-EISA inomthamo wezimbotshana ophakeme, indawo eqondile engcono kanye nokuzinza okungcono kokushisa.Ngokuzayo, indlela ye-EISA ingasetshenziswa ukulungisa indawo enkulu yokuvula i-MA enezinga eliphezulu lokuguqulwa kanye nokukhetha okuhle kakhulu ngaphandle kokusebenzisa i-ejenti yokuvuselela kabusha.
Ishadi lokugeleza elingu-1 lendlela ye-SA-EISA yokuhlanganiswa kwezinto ze-OMA
1.2.2 ezinye izinqubo
Ukulungiswa kwe-MA okuvamile kudinga ukulawula okunembile kwemingcele ye-synthesis ukuze kuzuzwe isakhiwo esicacile se-mesoporous, futhi ukukhishwa kwezinto zesifanekiso nakho kuyinselele, okwenza inqubo yokuhlanganiswa ibe nzima.Njengamanje, izincwadi eziningi zibike ukuhlanganiswa kwe-MA ngezifanekiso ezahlukene.Eminyakeni yamuva nje, ucwaningo lwalugxile kakhulu ekuhlanganiseni kwe-MA nge-glucose, i-sucrose nesitashi njengezifanekiso nge-aluminium isopropoxide esixazululweni se-aqueous.Iningi lalezi zinto ze-MA zenziwa ku-aluminium nitrate, i-sulfate ne-alkoxide njengemithombo ye-aluminium.I-MA CTAB nayo itholakala ngokuguqulwa okuqondile kwe-PB njengomthombo we-aluminium.I-MA enezakhiwo ezihlukile zesakhiwo, okungukuthi i-Al2O3)-1, i-Al2O3)-2 ne-al2o3Futhi inokuqina okuhle kwe-thermal.Ukwengezwa kwe-surfactant akushintshi ukwakheka kwekristalu okungokwemvelo kwe-PB, kodwa kushintsha imodi yokunqwabelanisa yezinhlayiya.Ukwengeza, ukwakheka kwe-Al2O3-3 kwakhiwe ukunamathela kwe-nanoparticles ezinzile i-PEG ye-solvent ye-organic noma i-aggregation ezungeze i-PEG.Kodwa-ke, ukusatshalaliswa kosayizi we-pore we-Al2O3-1 kuncane kakhulu.Ngaphezu kwalokho, ama-catalysts asekelwe ku-palladium alungiselelwe nge-MA yokwenziwa njenge-carrier.Ekuphenduleni komlilo we-methane, i-catalyst esekelwe yi-Al2O3-3 ibonise ukusebenza okuhle kwe-catalytic.
Ngokokuqala ngqa, i-MA enosayizi omncane wembotshana wokusabalalisa ilungiswe kusetshenziswa i-aluminium eshibhile necebile nge-aluminium black slag ABD.Inqubo yokukhiqiza ihlanganisa inqubo yokukhipha ekushiseni okuphansi kanye nokucindezela okuvamile.Izinhlayiya eziqinile ezisele enqubweni yokukhipha ngeke zingcolise imvelo, futhi zinganqwabelana ngengozi ephansi noma ziphinde zisetshenziswe njengokugcwalisa noma ukuhlanganisa ekufakweni kukakhonkolo.Indawo ethile engaphezulu ye-MA ehlanganisiwe ingu-123~162m2/g, Ukusatshalaliswa kosayizi wembotshana kuncane, irediyasi ephezulu ingu-5.3nm, futhi i-porosity ingu-0.37 cm3/g.Izinto ezibonakalayo zingusayizi we-nano futhi usayizi wekristalu cishe u-11nm.I-Solid-state synthesis iyinqubo entsha yokuhlanganisa i-MA, engasetshenziswa ukukhiqiza i-radiochemical absorbent ukuze isetshenziswe emtholampilo.I-Aluminium chloride, i-ammonium carbonate kanye ne-glucose izinto zokusetshenziswa zixutshwe ngesilinganiso se-molar esingu-1: 1.5: 1.5, futhi i-MA ihlanganiswe ukusabela kwe-mechanochemical okusha kwesimo esiqinile. %.
Ukufingqa, esikhathini esizayo, izifanekiso zamangqamuzana ezincane zingathuthukiswa ukuze kwakhiwe izakhiwo ze-pore ezinamazinga amaningi, zilungise kahle isakhiwo, i-morphology kanye nezindawo zamakhemikhali ezingaphezulu zezinto zokwakha, futhi zikhiqize indawo enkulu engaphezulu futhi yayala i-wormhole MA.Hlola izifanekiso ezishibhile nemithombo ye-aluminium, lungiselela inqubo yokuhlanganisa, ucacise indlela yokuhlanganisa futhi uqondise inqubo.
Indlela yokuguqula ye-2 MA
Izindlela zokusabalalisa ngokulinganayo izingxenye ezisebenzayo kusithwali se-MA zifaka ukukhulelwa, i-in-situ synthe-sis, imvula, ukushintshaniswa kwe-ion, ukuxutshwa komshini nokuncibilika, phakathi kwazo okubili kokuqala okuvame ukusetshenziswa kakhulu.
2.1 indlela ye-in-situ synthesis
Amaqembu asetshenziswa ekuguqulweni kokusebenza ayengezwa kunqubo yokulungiselela i-MA ukuze iguqule futhi izinze uhlaka lwamathambo ezinto futhi kuthuthukiswe ukusebenza kwe-catalytic.Inqubo ikhonjiswe kuMfanekiso 2. Liu et al.kuhlanganiswe i-Ni/Mo-Al2O3in situ nge-P123 njengesifanekiso.Kokubili u-Ni no-Mo bahlakazwe ngamashaneli e-MA ahlelekile, ngaphandle kokucekela phansi ukwakheka kwe-mesoporous kwe-MA, futhi ukusebenza kwe-catalytic ngokusobala kwathuthukiswa.Ukwamukela indlela yokukhula kwe-in-situ ku-gamma-al2o3substrate ehlanganisiwe,Uma iqhathaniswa ne-γ-Al2O3, i-MnO2-Al2O3 inendawo enkulu ye-BET ethize enkulu kanye nevolumu yembotshana, futhi inokwakheka kwe-mesoporous e-bimodal enokusabalalisa kosayizi wembotshana.I-MnO2-Al2O3 inezinga lokukhangisa elisheshayo nokusebenza kahle okuphezulu kwe-F-, futhi inebanga elibanzi le-pH lesicelo (pH=4~10), elifanele izimo zokusebenza ezisebenzayo zezimboni.Ukusebenza kokugaya kabusha kwe-MnO2-Al2O3 kungcono kunalokho kwe-γ-Al2O.Ukuzinza kwesakhiwo kudinga ukuthuthukiswa okwengeziwe.Ukufingqa, izinto eziguquliwe ze-MA ezitholwe nge-in-situ synthesis zinokuhleleka okuhle, ukusebenzisana okuqinile phakathi kwamaqembu nabathwali be-alumina, inhlanganisela eqinile, umthwalo omkhulu wezinto ezibonakalayo, futhi akulula ukubangela ukuchithwa kwezingxenye ezisebenzayo kwinqubo yokusabela kwe-catalytic. , futhi ukusebenza kwe-catalytic kuthuthukiswa kakhulu.
Umdwebo 2 Ukulungiswa kwe-MA esebenzayo ngokuhlanganisa kwe-in-situ
2.2 indlela yokukhulelwa
Ukucwilisa i-MA elungisiwe eqenjini eliguquliwe, kanye nokuthola impahla ye-MA eshintshiwe ngemva kokwelashwa, ukuze kubonakale imiphumela ye-catalysis, i-adsorption nokunye okunjalo.Cai et al.ilungiswe i-MA esuka ku-P123 ngendlela ye-sol-gel, futhi yacwiliswa kusisombululo se-ethanol ne-tetraethylenepentamine ukuze kutholwe i-amino modified MA impahla ngokusebenza okunamandla kwe-adsorption.Ngaphezu kwalokho, uBelkacemi et al.ecwiliswe ku-ZnCl2solution ngenqubo efanayo ukuze kutholwe i-zinc doped modified MA materials.Indawo ethile engaphezulu kanye nevolumu yembotshana ingu-394m2/g no-0.55 cm3/g, ngokulandelana.Uma kuqhathaniswa nendlela yokuhlanganisa ye-in-situ, indlela yokumilisela inokusabalalisa kwesici esingcono, isakhiwo esizinzile se-mesoporous nokusebenza okuhle kwe-adsorption, kodwa amandla okusebenzelana phakathi kwezingxenye ezisebenzayo nesithwali se-alumina abuthakathaka, futhi umsebenzi we-catalytic uphazanyiswa kalula izici zangaphandle.
3 inqubekelaphambili yokusebenza
Ukuhlanganiswa komhlaba ongavamile MA onezici ezikhethekile kuwumkhuba wokuthuthukiswa esikhathini esizayo.Njengamanje, kunezindlela eziningi zokuhlanganisa.Amapharamitha wenqubo athinta ukusebenza kwe-MA.Indawo ethile engaphezulu, ivolumu yembotshana kanye nobubanzi bembotshana ye-MA ingalungiswa ngohlobo lwesifanekiso nokwakheka kwe-aluminium eyandulela.Izinga lokushisa lokubala kanye nokugxila kwesifanekiso se-polymer kuthinta indawo ethile kanye nevolumu yembotshana ye-MA.I-Suzuki ne-Yamauchi yathola ukuthi izinga lokushisa lokubala linyusiwe lisuka ku-500℃ laya ku-900℃.Imbobo inganyuswa futhi indawo engaphezulu ingancishiswa.Ukwengeza, ukwelashwa kokuguqulwa komhlaba okungavamile kuthuthukisa umsebenzi, ukuzinza kokushisa okungaphezulu, ukuzinza kwesakhiwo kanye ne-acidity ebusweni bezinto ze-MA kunqubo ye-catalytic, futhi ihlangabezana nokuthuthukiswa kokusebenza kwe-MA.
3.1 I-Defluorination Adsorbent
I-fluorine emanzini okuphuza e-China iyingozi kakhulu.Ngaphezu kwalokho, ukwanda kokuqukethwe kwe-fluorine kusixazululo se-zinc sulfate yezimboni kuzoholela ekugqwaleni kwepuleti le-electrode, ukonakala kwendawo yokusebenza, ukwehla kwezinga le-zinc kagesi kanye nokuncipha kwenani lamanzi asetshenziswe kabusha ohlelweni lokwenza i-asidi. kanye nenqubo ye-electrolysis yesithando somlilo sombhede esosa igesi ye-flue.Njengamanje, indlela ye-adsorption iyona ekhangayo kakhulu phakathi kwezindlela ezivamile zokuchithwa kwamanzi.Nokho, kukhona ukushiyeka, njengomthamo ompofu we-adsorption, ububanzi obuncane be-pH obutholakalayo, ukungcola kwesibili nokunye.Ikhabhoni ecushiwe, i-amorphous alumina, i-alumina ecushiwe nezinye izikhangisi zisetshenziselwe ukuchithwa kwamanzi, kodwa izindleko zama-adsorbents ziphezulu, futhi umthamo we-adsorption wesixazululo se-F-in neutral noma ukugxila okuphezulu kuphansi. i-adsorbent efundisiwe yokukhishwa kwe-fluoride ngenxa yokuhlobana kwayo okuphezulu nokukhetha kwe-fluoride ngevelu ye-pH engathathi hlangothi, kodwa inqunyelwe umthamo ompofu we-adsorption we-fluoride, futhi ku-pH<6 kuphela lapho ingaba nokusebenza okuhle kwe-fluoride adsorption.MA idonse ukunaka okubanzi. ekulawuleni ukungcoliswa kwemvelo ngenxa yendawo yayo enkulu ethize, umphumela wesayizi wembotshana oyingqayizivele, ukusebenza kwe-acid-base, ukuzinza kokushisayo nokusetshenziswayo.Kundu et al.i-MA elungisiwe enomthamo omkhulu we-fluorine adsorption ongu-62.5 mg/g.Umthamo we-fluorine adsorption we-MA uthonywa kakhulu izici zayo zesakhiwo, njengendawo ethile yendawo, amaqembu asebenza phezulu, usayizi we-pore kanye nosayizi ophelele we-pore.Ukulungiswa kwesakhiwo nokusebenza kwe-MA kuyindlela ebalulekile yokuthuthukisa ukusebenza kwayo kwe-adsorption.
Ngenxa ye-asidi eqinile ye-La kanye nesisekelo esiqinile se-fluorine, kukhona ukuhlobana okuqinile phakathi kwe-La nama-ion fluorine.Eminyakeni yamuva nje, ezinye izifundo zithole ukuthi i-La njengesilungisi ingathuthukisa amandla e-adsorption e-fluoride.Kodwa-ke, ngenxa yokungaqini kahle kwesakhiwo sezinto eziyivelakancane ze-adsorbent zomhlaba, umhlaba ongavamile kakhulu ufakwa esixazululweni, okuholela ekungcolisweni kwamanzi okwesibili kanye nokulimala empilweni yomuntu.Ngakolunye uhlangothi, ukugcwala okuphezulu kwe-aluminium endaweni yamanzi kungenye yezinto ezinobuthi empilweni yomuntu.Ngakho-ke, kuyadingeka ukulungisa uhlobo lwe-adsorbent eyinhlanganisela ngokuzinza okuhle futhi akukho leaching noma ukukhishwa okuncane kwezinye izakhi kunqubo yokususa i-fluorine.I-MA elungiswe ngu-La no-Ce yalungiselelwa indlela yokukhulelwa (La/MA kanye ne-Ce/MA).ama-earth oxides angavamile alayishwa ngempumelelo ebusweni be-MA okokuqala ngqa, obunokusebenza okuphezulu kwe-defluorination. Izindlela eziyinhloko zokukhipha i-fluorine i-electrostatic adsorption kanye ne-chemical adsorption, ukukhanga kwe-electron ye-surface positive charge kanye ne-ligand exchange reaction ihlangana ne-surface hydroxyl, i- Iqembu elisebenzayo le-hydroxyl endaweni ye-adsorbent likhiqiza ibhondi ye-hydrogen nge-F-, ukuguqulwa kwe-La ne-Ce kuthuthukisa umthamo we-adsorption we-fluorine, i-La/MA iqukethe amasayithi e-hydroxyl adsorption engeziwe, futhi umthamo we-adsorption we-F ulandelana ne-La/MA >Ce/MA>MA.Ngokukhula kokugxila kokuqala, amandla okukhangisa e-fluorine ayanda.Umphumela we-adsorption ubangcono kakhulu uma i-pH ingu-5~9, kanye nenqubo yokukhangisa ye-fluorine ivumelana nemodeli ye-Langmuir isothermal adsorption.Ngaphezu kwalokho, ukungcola kwe-sulfate ions ku-alumina nakho kungathinta kakhulu izinga lamasampula.Nakuba ucwaningo oluhlobene mayelana ne-alumina eguquliwe yomhlaba engavamile lwenziwe, iningi locwaningo lugxile enqubweni ye-adsorbent, okunzima ukuyisebenzisa ezimbonini.Esikhathini esizayo, singafunda indlela yokuhlukanisa ye-fluorine complex in zinc sulfate solution. kanye nezici zokufuduka kwama-ion e-fluorine, thola i-adsorbent ye-fluorine ion esebenza kahle, engabizi kakhulu futhi evuselelekayo ye-defluorination yesisombululo se-zinc sulfate ohlelweni lwe-zinc hydrometallurgy, futhi isungule imodeli yokulawula inqubo yokwelapha isisombululo se-fluorine esiphezulu esisekelwe emhlabeni ongavamile MA nano adsorbent.
3.2 I-Catalyst
3.2.1 Ukuguqulwa okomile kwe-methane
Umhlaba ongavamile ungalungisa i-asidi (isisekelo) yezinto ezimbotshana, wandise isikhala somoya-mpilo, futhi uhlanganise ama-catalyst ngokuhlakazeka okufanayo, isikali se-nanometer nokuzinza.Ivamise ukusetshenziselwa ukusekela izinsimbi ezinhle nezinsimbi zoguquko ukuze kuthuthukiswe i-methanation ye-CO2.Njengamanje, izinto ezibonakalayo ze-mesoporous eziguquliwe zomhlaba eziyivelakancane zithuthukela ku-methane dry reforming (MDR), ukucekelwa phansi kwe-photocatalytic kwama-VOC kanye nokuhlanzwa kwegesi yomsila. Uma kuqhathaniswa nezinsimbi ezinhle (ezifana ne-Pd, Ru, Rh, njll.) nezinye izinsimbi zoguquko (njenge Co, Fe, njll.), I-Ni/Al2O3catalyst isetshenziswa kabanzi emsebenzini wayo ophezulu we-catalytic nokukhetha, ukuzinza okuphezulu nezindleko eziphansi ze-methane.Kodwa-ke, i-sintering kanye ne-carbon deposition ye-Ni nanoparticles ebusweni be-Ni/Al2O3 iholela ekuvalweni ngokushesha kwe-catalyst.Ngakho-ke, kuyadingeka ukwengeza ukusheshisa, ukuguqula isithwali se-catalyst futhi uthuthukise indlela yokulungiselela ukuze uthuthukise umsebenzi we-catalytic, ukuzinza kanye nokumelana nokushiswa.Ngokuvamile, ama-oxide omhlaba angavamile angasetshenziswa njengabagqugquzeli besakhiwo kanye ne-elekthronikhi kuma-catalysts ahlukahlukene, futhi i-CeO2 ithuthukisa ukuhlakazeka kwe-Ni futhi iguqule izakhiwo ze-metallic Ni ngokusebenzisa ukuxhumana okuqinile kokusekelwa kwensimbi.
I-MA isetshenziswa kakhulu ukuthuthukisa ukuhlakazwa kwezinsimbi, futhi inikeze ukuvimbela izinsimbi ezisebenzayo ukuvimbela ukuhlangana kwazo.I-La2O3 enomthamo ophezulu wokugcina umoya-mpilo ithuthukisa ukumelana kwekhabhoni enqubweni yokuguqula, futhi i-La2O3 ikhuthaza ukusakazeka kwe-Co ku-mesoporous alumina, enomsebenzi wokulungisa ophezulu kanye nokuqina.I-La2O3promoter inyusa umsebenzi we-MDR we-Co/MA catalyst, futhi i-Co3O4and CoAl2O4phases kwakheka endaweni ye-catalyst.Nokho, i-La2O3 ehlakazeke kakhulu inezinhlamvu ezincane ezingu-8nm~10nm.Enqubweni ye-MDR, ukusebenzisana kwe-in-situ phakathi kwe-La2O3 ne-CO2formed La2O2CO3mesophase, okudale ukuqedwa ngempumelelo kwe-CxHy endaweni ye-catalyst.I-La2O3 ithuthukisa ukuncishiswa kwe-hydrogen ngokunikeza ukuminyana kwama-electron aphezulu futhi ithuthukise isikhala somoya-mpilo ku-10%Co/MA.Ukwengezwa kwe-La2O3 kunciphisa amandla okusebenza abonakalayo we-CH4consumption.Ngakho-ke, izinga lokuguqulwa kwe-CH4 lenyuke laya ku-93.7% ku-1073K K. Ukwengezwa kwe-La2O3 kwathuthukisa umsebenzi we-catalytic, kwakhuthaza ukuncishiswa kwe-H2, kwenyusa isibalo sezindawo ezisebenzayo ze-Co0, kwakhiqiza ikhabhoni efakwe kancane futhi kwandisa isikhala somoya-mpilo saba ku-73.3%.
U-Ce kanye no-Pr basekelwe ku-Ni/Al2O3catalyst ngendlela yokufakwa kwevolumu elinganayo ku-Li Xiaofeng.Ngemva kokwengeza i-Ce ne-Pr, ukukhetha ku-H2 kunyukile futhi ukukhetha ku-CO kwehlile.I-MDR eshintshwe yi-Pr inekhono elihle kakhulu le-catalytic, futhi ukukhetha ku-H2 kukhuphuke kusuka ku-64.5% kuya ku-75.6%, kuyilapho ukukhetha ku-CO kwehle kusuka ku-31.4% u-Peng Shujing et al.kusetshenziswe indlela ye-sol-gel, i-Ce-modified MA yalungiswa nge-aluminium isopropoxide, isopropanol solvent kanye ne-cerium nitrate hexahydrate.Indawo ethile yomkhiqizo inyuswe kancane.Ukwengezwa kwe-Ce kunciphise ukuhlanganiswa kwama-nanoparticles afana nenduku endaweni ye-MA.Amanye amaqembu e-hydroxyl ebusweni be-γ- Al2O3 ngokuyisisekelo embozwe yinhlanganisela ye-Ce.Ukuzinza okushisayo kwe-MA kwathuthukiswa, futhi akukho ukuguqulwa kwesigaba sekristalu okwenzeka ngemva kokubala ku-1000℃ amahora angu-10. U-Wang Baowei et al.kulungiswe i-MA material CeO2-Al2O4by coprecipitation method.I-CeO2 enezinhlamvu ezincane ze-cubic yahlakazwa ngokufanayo ku-alumina.Ngemva kokweseka u-Co no-Mo ku-CeO2-Al2O4, ukusebenzisana phakathi kwe-alumina nengxenye esebenzayo i-Co no-Mo kwavinjwa ngempumelelo yi-CEO2.
Abagqugquzeli bomhlaba abangavamile (La, Ce, y kanye no-Sm) Bahlanganiswe ne-Co/MA catalyst ye-MDR, futhi inqubo ikhonjiswe kumfanekiso.3. abagqugquzeli bomhlaba abangavamile bangathuthukisa ukusakazeka kwe-Co ku-MA yenethiwekhi futhi bavimbele ukuhlangana kwezinhlayiya ze-co.usayizi wezinhlayiyana ezincane, kuqina ukusebenzisana kwe-Co-MA, kuqina amandla okwenza i-catalytic kanye ne-sintering ku-YCo/MA catalyst, kanye nemiphumela emihle yabagqugquzeli abaningana emsebenzini we-MDR kanye ne-carbon deposition.Fig.I-4 i-HRTEM iMage ngemva kokwelashwa kwe-MDR ku-1023K, Co2: ch4: N2 = 1 ∶ 1 ∶ 3.1 amahora angu-8.Izinhlayiya ze-Co zikhona ngesimo samachashazi amnyama, kuyilapho abathwali be-MA bakhona ngesimo se-gray, okuncike kumehluko we-electron density.esithombeni se-HRTEM esino-10% Co/MA (umkhiwane 4b), i-agglomeration yezinhlayiya ze-Co metal ibonwa kubathwali be-maUkwengezwa komgqugquzeli womhlaba ongavamile kunciphisa izinhlayiya ze-Co ku-11.0nm~12.5nm.I-YCo/MA inokusebenzisana okuqinile kwe-Co-MA, futhi ukusebenza kwayo kokucula kungcono kunezinye izisusa.ngaphezu kwalokho, njengoba kuboniswe kumakhiwane.I-4b kuya ku-4f, i-hollow carbon nanowires (CNF) ikhiqizwa kuma-catalysts, ahlala ethintana nokugeleza kwegesi futhi avimbele i-catalyst ukuthi ingasebenzi.
Umdwebo 3 Umthelela wokwengezwa komhlaba ongavamile ezimpahleni ezibonakalayo namakhemikhali kanye nokusebenza okunamandla kwe-MDR kwe-Co/MA catalyst
3.2.2 I-deoxidation catalyst
I-Fe2O3/Meso-CeAl, i-Ce-doped Fe-based deoxidation catalyst, yalungiswa nge-oxidative dehydrogenation ye-1-butene ene-CO2as oxidant ethambile, futhi yasetshenziswa ekuhlanganiseni kwe-1,3- butadiene (BD).I-Ce yahlakazeka kakhulu ku-alumina matrix, futhi i-Fe2O3/meso yahlakazeka kakhuluFe2O3/Meso-CeAl-100 catalyst ayinayo nje kuphela izinhlobo zensimbi ezihlakazeke kakhulu kanye nezakhiwo ezinhle zesakhiwo, kodwa futhi inamandla okugcina umoya-mpilo omuhle, ngakho inamandla okukhangisa namandla okwenza kusebenze. kwe CO2.Njengoba kukhonjisiwe kuMfanekiso 5, izithombe ze-TEM zibonisa ukuthi i-Fe2O3/Meso-CeAl-100 ivamileKubonisa ukuthi isakhiwo sesiteshi esinjenge-worm se-MesoCeAl-100 sikhululekile futhi sine-porous, esizuzisa ekuhlakazweni kwezithako ezisebenzayo, kuyilapho i-Ce ihlakazeke kakhulu. ifakwe ngempumelelo ku-alumina matrix.Izinto zokumboza zensimbi ezisezingeni eliphansi ezihlangabezana nezinga lezimoto ezikhipha umoya ophansi kakhulu sezenze ukwakheka kwezimbotshana, ukuzinza okuhle kwe-hydrothermal kanye nomthamo omkhulu wokugcina umoya-mpilo.
3.2.3 I-Catalyst Yezimoto
I-Pd-Rh isekela ama-quaternary aluminium-based arare earth complexes i-AlCeZrTiOx ne-AlLaZrTiOx ukuze ithole izinto zokumboza zezimoto.I-mesoporous aluminium-based arare earth complex Pd-Rh/ALC ingasetshenziswa ngempumelelo njengesisusa sokuhlanzwa kwe-exhaust yemoto ye-CNG ehlala isikhathi eside, kanye nokusebenza kahle kokuguqulwa kwe-CH4, okuyingxenye eyinhloko ye-CNG yegesi yokukhipha imoto, iphezulu njengo-97.8%.Sebenzisa indlela yesinyathelo esisodwa se-hydrotherMAl ukuze ulungiselele leyo mpahla eyinhlanganisela yomhlaba eyivelakancane ukuze ikwazi ukuzihlanganisa,Izandulela ezi-odelwe ze-mesoporous ezinesimo esimetastable kanye nokuhlanganisa okuphezulu zahlanganiswa, futhi ukuhlanganiswa kwe-RE-Al kwahambisana nemodeli “yeyunithi yokukhula eyinhlanganisela” , ngaleyo ndlela ibona ukuhlanzwa kwesiguquli se-catalytic se-automobile post-mounted three-way catalytic converter.
Umfanekiso 4 wezithombe ze-HRTEM zika-ma (a), Co/ MA(b), LaCo/MA(c), CeCo/MA(d), YCo/MA(e) kanye ne-SmCo/MA(f)
Umfanekiso wesi-5 we-TEM (A) kanye nomdwebo wesici se-EDS (b,c) we-Fe2O3/Meso-CeAl-100
3.3 ukusebenza okukhanyayo
Ama-electron ezinto ezingavamile zomhlaba ajabulela kalula ukushintsha phakathi kwamazinga ahlukene wamandla futhi akhiphe ukukhanya.Ama-ion omhlaba angavamile avame ukusetshenziswa njengezicishazi ukulungisa izinto ezikhanyayo.Ama-ion omhlaba ayivelakancane angalayishwa phezu kwama-microspheres angenalutho e-aluminium phosphate ngokusebenzisa indlela ye-coprecipitation kanye nendlela yokushintshanisa i-ion, kanye nezinto zokukhanya ze-AlPO4∶RE(La,Ce,Pr,Nd) zingalungiswa.I-wavelength ye-luminescent isendaweni eseduze ye-ultraviolet.MA yenziwe amafilimu amancane ngenxa ye-inertia yayo, i-dielectric engaguquki ephansi kanye ne-conductivity ephansi, okwenza isebenze kumadivayisi kagesi kanye ne-optical, amafilimu amancane, izithiyo, izinzwa, njll. Ingakwazi futhi zisetshenziselwe ukuzwa impendulo amakristalu ezithombe ezinohlangothi olulodwa, ukukhiqizwa kwamandla kanye nama-anti-reflection coatings.Lawa madivayisi angamafilimu astakiwe anobude obuqondile bendlela yokubona, ngakho-ke kuyadingeka ukulawula inkomba ye-refractive kanye nogqinsi.Okwamanje, i-titanium dioxide ne-zirconium oxide ene-high refractive index kanye ne-silicon dioxide ene-low refractive index kuvame ukusetshenziselwa ukuklama nokwakha amadivaysi anjalo. .Uhlu olutholakalayo lwezinto ezinezici zamakhemikhali angaphezulu luyanwetshwa, okwenza kube nokwenzeka ukuklama izinzwa ze-photon ezithuthukisiwe.Ukwethulwa kwamafilimu e-MA kanye ne-oxyhydroxide ekwakhiweni kwemishini yokubona kubonisa amandla amakhulu ngoba inkomba ye-refractive ifana neye-silicon dioxide.Kodwa izakhiwo zamakhemikhali zihlukile.
3.4 ukuzinza kwe-thermal
Ngokukhuphuka kwezinga lokushisa, i-sintering ithinta kakhulu umphumela wokusetshenziswa kwe-MA catalyst, futhi indawo ethize iyancipha futhi isigaba sekristalline esingu-γ-Al2O3in sishintsha sibe yizigaba zika-δ kanye no-θ kuya ku-χ.Izinto zomhlaba ezingavamile zinokuzinza okuhle kwamakhemikhali kanye nokuzinza kokushisa, ukuguquguquka okuphezulu, nezinto zokusetshenziswa ezitholakala kalula nezishibhile.Ukwengezwa kwezakhi zomhlaba ezingavamile kungathuthukisa ukuzinza kokushisa, ukumelana nokushisa okuphezulu kwe-oxidation kanye nezakhiwo zemishini zenkampani yenethiwekhi, futhi kulungise i-asidi engaphezulu ye-carrier.La no-Ce yizinto ezisetshenziswa kakhulu futhi ezifundwayo zokuguqulwa.U-Lu Weiguang nabanye bathola ukuthi ukwengezwa kwezakhi zomhlaba ezingavamile kuvimbele ngempumelelo ukusakazeka kwezinhlayiya ze-alumina ngobuningi, i-La no-Ce ivikele amaqembu e-hydroxyl ebusweni be-alumina, i-sintering evinjiwe kanye nokuguqulwa kwesigaba, futhi yehlisa umonakalo wokushisa okuphezulu kusakhiwo se-mesoporous. .I-alumina elungisiwe isenayo indawo ephakeme ethize ephezulu kanye nevolumu yembotshana.Nokho, ingxenye enkulu yomhlaba engavamile kakhulu noma encane kakhulu izonciphisa ukuzinza okushisayo kwe-alumina.U-Li Yanqiu et al.ingeze i-5% La2O3to γ-Al2O3, ethuthukise ukuzinza kwe-thermal futhi yandisa umthamo we-pore kanye nendawo ethile yendawo ye-alumina carrier.Njengoba kungabonwa kuMfanekiso 6, i-La2O3 yengezwe ku-γ-Al2O3,Thuthukisa ukuzinza okushisayo kwesithwali esiyinhlanganisela yomhlaba esingavamile.
Enqubweni yokwenza izinhlayiya ze-nano-fibrous ezine-La kuya ku-MA, indawo engaphezulu ye-BET kanye nevolumu ye-pore ye-MA-La iphakeme kunaleyo ye-MA lapho izinga lokushisa lokwelashwa likhuphuka, futhi ukusebenzisa i-La kunomphumela osobala wokuhlehlisa ekushiseni phezulu. izinga lokushisa.njengoba kuboniswe emkhiwaneni.I-7, ngokukhuphuka kwezinga lokushisa, i-La ivimbela ukusabela kokukhula okusanhlamvu nokuguqulwa kwesigaba, kuyilapho amakhiwane.I-7a kanye ne-7c ibonisa ukuqoqwa kwezinhlayiya ze-nano-fibrous.emkhiwaneni.7b, ububanzi bezinhlayiya ezinkulu ezikhiqizwe ngokubala ku-1200℃ cishe bungu-100nm.Kubonisa ukucwiliswa okubalulekile kwe-MA.Ngaphezu kwalokho, uma kuqhathaniswa ne-MA-1200, i-MA-La-1200 ayihlanganisi ngemva kokwelashwa kokushisa.Ngokungezwa kwe-La, izinhlayiya ze-nano-fiber zinekhono elingcono lokucwilisa.ngisho nasezingeni lokushisa eliphakeme lokubala, i-doped La isahlakazeke kakhulu endaweni ye-MA.I-La modified MA ingasetshenziswa njengesithwali se-Pd catalyst ku-C3H8oxidation reaction.
Umdwebo 6 Imodeli yesakhiwo ye-alumina ecwengayo enezici zomhlaba eziyivelakancane nangaphandle kwayo
Umfanekiso wesi-7 wezithombe ze-TEM ze-MA-400 (a), MA-1200(b), MA-La-400(c) kanye ne-MA-La-1200(d)
4 Isiphetho
Inqubekelaphambili yokulungiswa kanye nokusetshenziswa kokusebenza kwezinto ezingavamile ze-MA eziguquliwe emhlabeni ziyethulwa.I-Rare Earth modified MA isetshenziswa kakhulu.Nakuba ucwaningo oluningi selwenziwe ekusetshenzisweni kwe-catalytic, ukuzinza kwe-thermal kanye ne-adsorption, izinto eziningi zinezindleko eziphezulu, inani eliphansi le-doping, ukuhleleka okungalungile futhi kunzima ukwenziwa yizimboni.Umsebenzi olandelayo kufanele wenziwe esikhathini esizayo: thuthukisa ukwakheka kanye nesakhiwo se-MA eguquliwe yomhlaba eyivelakancane, khetha inqubo efanele, Hlangana nokuthuthukiswa kokusebenza;Ukusungula imodeli yokulawula inqubo esekelwe enqubweni yokusebenza ukuze kuncishiswe izindleko kanye nokuqaphela ukukhiqizwa kwezimboni;Ukuze kwandiswe izinzuzo zezinsiza zomhlaba ezingavamile zaseShayina, kufanele sihlole indlela yokuguqulwa kwe-rare earth MA, sithuthukise ithiyori kanye nenqubo yokulungiselela i-rare earth modified MA.
Iphrojekthi Yesikhwama: Iphrojekthi Yesayensi Nobuchwepheshe Yokuqamba Iphelele ye-Shaanxi (2011KTDZ01-04-01);Isifundazwe sase-Shaanxi 2019 Iphrojekthi Ekhethekile Yocwaningo Lwesayensi (19JK0490);2020 iphrojekthi ekhethekile yocwaningo lwesayensi yase-Huaqing College, i-Xi 'an University of Architecture and Technology (20KY02)
Umthombo: Umhlaba Ongavamile
Isikhathi sokuthumela: Jul-04-2022