Ukusebenza kwe-Alumina Powder njengoSekelo lwe-Catalyst
Uma sixoxa ngemboni yamakhemikhali, ikakhulukazi insimu ye-catalysis, kuningi okuhilelekile. Namuhla, ngeke sikhulume ngalezo zingxenye zensimbi ezisebenzayo ezisezingeni eliphezulu, ezisonta ulimi, kodwa kunalokho "iqhawe elingadunyiswa" elivame ukunganakwa kodwa elibaluleke kakhulu - i-alumina powder. Kufana nensika yesiteji, noma isisekelo sesakhiwo; ukuthi izingxenye ezisebenzayo, lezo "zinkanyezi," zisebenza kahle kangakanani kuncike ngokuphelele ekutheni isiteji sakhiwe kahle kangakanani.
Ngesikhathi ngiqala ukungena kule nsimu, ngakuthola kungavamile futhi—kunganii-aluminaikakhulukazi? Kuzwakala kungavamile, pho kungani kuthatha indawo ebaluleke kangaka embonini yokusekela i-catalyst? Kamuva, ngemva kokuchitha isikhathi eside nabasebenzi abanolwazi elabhorethri naseshabhu, kancane kancane ngaqonda. Akuyona inketho "engcono kakhulu", kodwa kunalokho inketho "elinganiselayo kakhulu" etholakala phakathi kokusebenza, izindleko, kanye nokusetshenziswa okusebenzayo. Lokhu kufana nokuthenga imoto; asidingi ngempela eshesha kakhulu, kodwa kunalokho sidinga elinganisela ukusetshenziswa kahle kukaphethiloli, isikhala, ukuqina, kanye nentengo. Embonini yezinkampani ezithwala impahla, i-alumina ifana naleyo "ephelele" - ubuthakathaka obuncane kanye namandla avelele.
Okokuqala, kumelwe sincome ikhwalithi yaso “yesiponji esinezimbobo”—indawo enkulu kanye nekhono lokukhula eliphezulu kakhulu.
Lokhu kungamandla ayinhlokoimpuphu ye-alumina. Ungacabangi ukuthi inhlama eqinile neqinile oyisebenzisa ekhaya. Ngemva kokucubungula okukhethekile, ingaphakathi le-alumina carrier ligcwele ama-micropores kanye neziteshi ku-nanoscale. Lesi sakhiwo sibizwa ngokuthi "indawo ephezulu ethile."
Isibonelo, igremu elilodwa lempuphu ye-alumina esezingeni eliphezulu, ukube zonke izimbobo zayo zangaphakathi bezinwetshwe ngokugcwele, bezingafinyelela kalula kumamitha-skwele angamakhulu amaningana endaweni engaphezulu—zinkulu kunenkundla yebhasikithi! Cabanga ukuthi zingaki izingxenye ezisebenzayo (njengeplatinum, i-palladium, ne-nickel) ezingafakwa “endaweni enkulu kangaka”! Kufana nokuhlinzeka izingxenye ezisebenzayo “ngendlu yokulala” enkulu kakhulu, enefenisha enhle, ezivumela ukuba zihlakazeke ngokulinganayo futhi zigweme ukuhlangana ndawonye, ngaleyo ndlela zikhulise ukuvezwa kwazo kanye nokuxhumana nama-reactants. Lokhu kuqinisekisa ngokuyisisekelo ukusebenza kahle kwe-catalytic.
Ngaphezu kwalokho, isakhiwo sembobo salesi "siponji" singenziwa "ngokwezifiso." Ngokulungisa inqubo yokulungiselela, singalawula usayizi, ukusatshalaliswa, kanye nesimo sembobo zayo ngezinga elithile, njengobumba olubumbayo. Amanye ama-molecule asabelayo makhulu futhi adinga "iminyango" emikhulu ukuze ingene; eminye imizwa iyashesha futhi idinga imbobo emifushane ukuze igweme ukulahleka enkingeni. Ukusekelwa kwe-alumina kungahlangabezana ngokuphelele nalezi "zidingo ezenzelwe wena," ukuguquguquka okungenakuqhathaniswa nezinye izinto eziningi.
Okwesibili, "isimo sayo esihle" kufanelekile ukusho—inokuqina kwamakhemikhali okuhle kakhulu kanye namandla okusebenza.
Indawo lapho kuhlala khona ama-catalyst ayikhululekile neze. Ngokuvamile kuba nokushisa okuphezulu kanye nengcindezi, futhi ngezinye izikhathi kuhilela ngisho nokuchayeka kumagesi agqwalisayo. Cabanga ukube ukusekelwa ngokwako bekuyi-"target soft," kudilika zingakapheli izinsuku ezimbili ku-reactor, noma kusabela ngamakhemikhali ngezingxenye ezisebenzayo kanye nama-reactant—ingabe konke bekungeke kube senkingeni?
Impuphu ye-alumina, kulokhu, “izinzile” ngendlela emangalisayo. Igcina isakhiwo sayo sekristalu ngisho nasemazingeni okushisa aphezulu, imelana nokuwa, futhi izakhiwo zayo zamakhemikhali “azithathi hlangothi”, azikwazi ukusabela kalula nezinye izinto. Lokhu kuqinisekisa isikhathi eside sokuphila kwe-catalyst, okusindisa amafektri isikhathi sokungasebenzi kanye nezindleko zokushintsha.
Ngaphezu kwalokho, cabanga ngamandla emishini. Kuma-reactor ezimboni, ama-catalyst awamane amiswe; avame ukudinga ukumelana nomthelela wokugeleza komoya, ukungqubuzana phakathi kwezinhlayiya, ngisho nokuwa ngaphakathi kombhede ohambayo. Uma amandla enganele, azoqhekeka abe yimpuphu ngesikhathi sokuthuthwa, noma aphenduke umlotha ngokushesha nje lapho engena ku-reactor—yimuphi umgudu ongawufeza?I-Aluminaizisekelo, ngemva kokubumba kanye nokugaya, zithuthukisa amandla anele okumelana nalezi “zinhlupho,” okuqinisekisa ukusebenza kwesikhathi eside nokuzinzile kwedivayisi yokusabela. Yilokhu okushiwo izisebenzi ezinolwazi uma zithi “le catalyst iqinile.”
Ngaphezu kwalokho, iyakwazi ukumelana nezimo ezinzima kakhulu—izakhiwo zayo ezingaphezulu zisebenza kakhulu.
Ubuso be-alumina abubushelelezi. Buqukethe izindawo ezine-asidi noma eziyisisekelo. Lezi zindawo ngokwazo zinamandla okuvuselela ukusabela kwezinye izinto. Okubaluleke kakhulu, zingasebenzisana nensimbi esebenzayo esekelwayo—into esiyibiza ngokuthi ukusebenzisana.
Lokhu kusebenzisana kunezinzuzo eziningi. Ngakolunye uhlangothi, kusebenza “njengeglue,” kunamathela ngokuqinile “izinhlayiya zensimbi ekusekelweni, kuzivimbele ukuthi zinyakaze, zihlangane, futhi zikhule emazingeni okushisa aphezulu (lokhu kubizwa ngokuthi ukuthungula). Uma ukuthungula kwenzeka, umsebenzi wokuthungula wehla kakhulu. Ngakolunye uhlangothi, ngezinye izikhathi kungashintsha isimo se-elekthronikhi sezinhlayiya zensimbi, kuzenze zisebenze kangcono ekuphenduleni kokuthungula, kufezwe umphumela wokubambisana “1+1>2″”.
Yiqiniso, akukho okuphelele. Izisekelo ze-Alumina nazo azinawo amaphutha. Isibonelo, ezindaweni ezishisa kakhulu ezinomusi wamanzi, zingase zibe "noshintsho lwesigaba," zishintshe kusukela kuhlobo lwe-γ olusebenzayo kakhulu ziye kuhlobo lwe-α olungasebenzi kakhulu, okuholela ekuweni kwesakhiwo se-pore kanye nokwehla okukhulu kwendawo engaphezulu. Lokhu kufana ne-activated carbon eshiswa ibe yi-graphite; yize iseyi-carbon, amandla ayo okumunca ahluke kakhulu. Ngakho-ke, abacwaningi bebesebenza ukuthuthukisa ukuzinza kwayo kokushisa ngokuyixuba nezinye izakhi (njenge-silicon ne-zirconium) noma ukuthuthukisa izinqubo ezintsha zokulungiselela ukuze kwandiswe amandla ayo futhi kuncishiswe ubuthakathaka bayo.
Ngakho-ke, uyabona, le mpuphu emhlophe ebonakala ijwayelekile iqukethe ulwazi oluningi. Akuyona ubuchwepheshe obumnyama obungenakulinganiswa, kodwa yilolu hlobo lwezinto ezibonakalayo, olulwela ukulinganisela nokwenza ngcono yonke imininingwane, olusekela ingxenye yesistimu yesimanje yezimboni yokukhiqiza. Kusukela ekuhlanzeni ukukhishwa kwezimoto kuya ekuqhekekeni nasekuguquleni uphethiloli, kanye nokuhlanganiswa kwezinto zokusetshenziswa zamakhemikhali ahlukahlukene, umsebenzi othule wabathwali be-alumina cishe ubonakala njalo ngemuva kwezigcawu.
Ayikhanyi njengezinsimbi eziyigugu njengeplatinum noma i-palladium, futhi intengo yayo iphansi kakhulu, kodwa ukuthembeka kwayo, ukuqina kwayo, kanye nokusebenza kahle kwayo ngezindleko eziphezulu kwenza kube yisisekelo esiqinile kakhulu sezicelo ezinkulu zezimboni. Ngesikhathi esizayo lapho uzwa ngentuthuko kwezobuchwepheshe be-catalytic, yinikeze isithupha sakho, ngoba i-alumina powder, iqhawe elingadunyiswanga ngemuva kwezigcawu, lifanelwe isabelo esikhulu sodumo ngale mpumelelo.