Ukusabela kwamakhemikhali kwenzeka nxazonke zethu ngaso sonke isikhathi—kusobala uma ucabanga ngakho, kodwa bangaki kithi abakwenzayo lapho siqala imoto, sibilisa iqanda, noma sifaka umanyolo etshanini lethu?
Uchwepheshe we-Chemical Catalysis uRichard Kong ubelokhu ecabanga nge-chemical reactions. Emsebenzini wakhe “njengomlungisi wobungcweti,” njengoba esho, akagcini nje ngokuba nesithakazelo ezimpendulweni ezivela zodwa, kodwa futhi nasekutholeni izimpendulo ezintsha.
Njengomfundi waseKlarman kwiKhemistri kanye neBiology yamakhemikhali eKolishi Lobuciko Nesayensi, uKong usebenza ukuthuthukisa izinto ezikhuthaza ukusabela kwamakhemikhali emiphumeleni efiselekayo, edala imikhiqizo ephephile futhi enenani elongeziwe, okuhlanganisa naleyo engaba nomthelela omuhle empilweni yomuntu. ngoLwesithathu.
“Inani elikhulu lokusabela kwamakhemikhali lenzeka ngaphandle kosizo,” kusho uKong, ebhekisela ekukhishweni kwe-carbon dioxide lapho izimoto zishisa uphethiloli. “Kodwa ukusabela kwamakhemikhali okuyinkimbinkimbi nokuyinkimbinkimbi akwenzeki ngokuzenzakalelayo. Yilapho i-catalysis yamakhemikhali iqala khona.”
UKing nozakwabo bathuthukise ama-catalyst ukuqondisa ukusabela ababefuna kwenzeke. Isibonelo, i-carbon dioxide ingaguqulwa ibe yi-formic acid, i-methanol, noma i-formaldehyde ngokukhetha i-catalyst efanele kanye nokuhlola izimo zokusabela.
Ngokusho kukaKyle Lancaster, uSolwazi weKhemistri kanye neBiology yamakhemikhali (A&S) kanye nomqondisi kaKong, indlela kaKong ihambisana kahle nendlela "eqhutshwa ukutholakala" yelebhu kaLancaster. "URichard wayenomqondo wokusebenzisa i-tin ukuthuthukisa ikhemistri yakhe, okwakungakaze kube seskripthi sami," kusho uLancaster. "Une-catalyst engashintsha ngokukhetha i-carbon dioxide, okukhulunywa ngayo kakhulu emaphephandabeni, ibe yinto eyigugu kakhulu."
UKing kanye nabalingani bakhe basanda kuthola uhlelo, ngaphansi kwezimo ezithile, olungaguqula i-carbon dioxide ibe yi-formic acid.
“Ngenkathi singakabi sezingeni eliphezulu ekuphenduleni, uhlelo lwethu lungenziwa ngokwezifiso kakhulu,” kusho uKong. “Ngale ndlela, singaqala ukuqonda ngokujulile ukuthi kungani amanye ama-catalyst esebenza ngokushesha kunezinye, ukuthi kungani amanye ama-catalyst engcono ngokwemvelo. Singakwazi ukushintsha amapharamitha ama-catalyst bese sizama ukuqonda ukuthi yini eyenza lezi zinto zisebenze ngokushesha, ngoba lapho zisebenza ngokushesha, lapho zisebenza kangcono, kulapho ungakha khona ama-molecule ngokushesha.”
Njengomuntu waseKlarman, uKong usebenza futhi ukususa ama-nitrate, umanyolo ovamile ogeleza ngendlela enobuthi emifuleni yamanzi, emvelweni bese uwaguqula abe izinto ezingenabungozi, kusho yena.
UKing wazama ukusebenzisa izinsimbi ezitholakala emhlabeni, njenge-aluminium ne-tin, njengezinto ezibangela ukwakheka kwezinto. Izinsimbi zishibhile, azinabo ubuthi futhi ziningi kakhulu ongqimbeni lomhlaba, ngakho ukuzisebenzisa ngeke kube nezinkinga zokusimama, kusho yena.
“Sisebenza futhi ekutheni singazenza kanjani izinto ezibangela ukusabela lapho izinsimbi ezimbili zihlangana khona,” kusho uKong. “Ngokusebenzisa izinsimbi ezimbili ohlakeni olulodwa, yiziphi izindlela zokusabela kanye nezinqubo zamakhemikhali ezithakazelisayo esingazithola ezinhlelweni ze-bimetallic?”
Amahlathi ayindawo yamakhemikhali egcina lezi zinsimbi - abalulekile ekuvuleni amandla alezi zinsimbi ukuze zenze umsebenzi wazo, njengoba nje udinga izingubo ezifanele zesimo sezulu esifanele, kusho uKong.
Eminyakeni engama-70 edlule, indinganiso ibilokhu iwukusebenzisa isikhungo sensimbi esisodwa ukuze kufezwe izinguquko zamakhemikhali, kodwa eminyakeni eyishumi edlule noma ngaphezulu, osokhemisi kulo mkhakha baqale ukuhlola ukuhlangana kwezinsimbi ezimbili, kungaba ngamakhemikhali noma eduze. Okokuqala, kusho uKong, “Kukunika amazinga engeziwe enkululeko.”
Lezi zikhuthazi ze-bimetallic zinika osokhemisi ikhono lokuhlanganisa izikhuthazi zensimbi ngokusekelwe emandleni kanye nobuthakathaka bazo, kusho uKong. Isibonelo, isikhungo sensimbi esibopha kabi kuma-substrate kodwa siphula izibopho kahle singasebenza nesinye isikhungo sensimbi esiphula izibopho kabi kodwa sibopha kahle kuma-substrate. Ukuba khona kwensimbi yesibili nakho kuthinta izakhiwo zensimbi yokuqala.
“Ungaqala ukuthola lokho esikubiza ngokuthi umphumela wokubambisana phakathi kwezikhungo ezimbili zensimbi,” kusho uKong. “Insimu ye-bimetallic catalysis isivele iqala ukukhombisa ukusabela okuyingqayizivele nokumangalisayo.”
UKing uthe kusenezingqinamba eziningi mayelana nendlela izinsimbi ezihlangana ngayo kuma-molecule compounds. Ujabule kakhulu ngobuhle be-chemistry uqobo njengoba naye ejabule ngemiphumela. UKing walethwa eLancaster Laboratories ngenxa yobuchwepheshe bakhe ku-X-ray spectroscopy.
“Kuyi-symbiosis,” kusho uLancaster. “I-X-ray spectroscopy yasiza uRichard ukuqonda ukuthi kwenzekani ngemuva kwezigcawu nokuthi yini eyenza i-tin isebenze kahle futhi ikwazi ukusabela ngale ndlela yamakhemikhali. Sizuze olwazini lwakhe olubanzi lwe-chemistry yeqembu elikhulu, olwavula ithuba leqembu endaweni entsha.”
Konke kuncike kumakhemikhali ayisisekelo kanye nocwaningo, kusho uKong, futhi le ndlela yenziwe yaba nokwenzeka nge-Open Klarman scholarship.
“Ngosuku olujwayelekile, ngingenza ukusabela elabhorethri noma ngihlale kukhompyutha ngilinganisa ama-molecule,” kusho yena. “Sizama ukuthola isithombe esiphelele ngangokunokwenzeka somsebenzi wamakhemikhali.”