I-catalyst esebenza kahle kakhulu eguqula igesi ye-propane ibe ama-hydrocarbon esinda kakhulu ithuthukiswe yi-King Abdullah University of Science and Technology yase-Saudi Arabia. (KAUST) abacwaningi. Isheshisa kakhulu ukusabela kwamakhemikhali okwaziwa ngokuthi i-alkane metathesis, engase isetshenziselwe ukukhiqiza izinto zokubasa eziwuketshezi.

I-catalyst ihlela kabusha i-propane, equkethe ama-athomu ekhabhoni amathathu, ibe amanye ama-molecule, njenge-butane (equkethe amakhabhoni amane), i-pentane (enamakhabhoni amahlanu) kanye ne-ethane (enamakhabhoni amabili). "Inhloso yethu ukuguqula ama-alkanes anesisindo esiphansi abe ama-alkane abalulekile ebanga likadizili," kusho uManoja Samantaray we-KAUST Catalysis Center.

Enhliziyweni ye-catalyst kunezinhlanganisela zezinsimbi ezimbili, i-titanium ne-tungsten, ezigxilwe endaweni ye-silica ngama-athomu omoya-mpilo. Isu elisetshenzisiwe laliyi-catalysis by design. Ucwaningo lwangaphambilini lubonise ukuthi ama-monometallic catalysts ayesebenza emisebenzini emibili: i-alkane kuya ku-olefin bese kuba yi-olefin metathesis. I-Titanium yakhethwa ngenxa yekhono layo lokwenza kusebenze ibhondi ye-CH kapharafini ukuze iguqule ibe yi-olefins, futhi i-tungsten yakhethwa ngenxa yomsebenzi wayo ophezulu we-olefin metathesis.

Ukwakha i-catalyst, ithimba lashisisa i-silica ukuze lisuse amanzi amaningi ngangokunokwenzeka lase lingeza i-hexamethyl tungsten ne-tetraneopentyl titanium, lenza impushana ephuzi ngokukhanyayo. Abacwaningi bafunde i-catalyst besebenzisa i-spectroscopy ye-nuclear magnetic resonance (NMR) ukukhombisa ukuthi ama-athomu e-tungsten ne-titanium alele eduze kakhulu endaweni ye-silica, mhlawumbe esondele kakhulu njenge-≈0.5 nanometres.

Abacwaningi, beholwa nguMqondisi walesi sikhungo uJean-Marie Basset, base behlola i-catalyst ngokuyifudumeza ku-150 ° C nge-propane izinsuku ezintathu. Ngemva kokuthuthukisa izimo zokusabela—ngokwesibonelo, ngokuvumela i-propane ukuthi igeleze ngokuqhubekayo phezu kwe-catalyst—bathole ukuthi imikhiqizo eyinhloko yokusabela kwakuyi-ethane ne-butane nokuthi ipheya ngalinye lama-athomu e-tungsten ne-titanium lingadala isilinganiso semijikelezo engu-10 000 ngaphambili. ukulahlekelwa umsebenzi wabo. Le "nombolo yenzuzo" iphezulu kakhulu eyake yabikwa ngokusabela kwe-propane metathesis.

Le mpumelelo ye-catalysis ngokuklama, abacwaningi bahlongoza, kungenxa yomphumela wokubambisana olindelekile phakathi kwezinsimbi ezimbili. Okokuqala, i-athomu ye-titanium ikhipha ama-athomu e-hydrogen ku-propane enze i-propene bese i-athomu ye-tungsten engumakhelwane igqabula i-propene ebhondini yayo ephindwe kabili ye-carbon-carbon, idale izingcezu ezingase zihlangane zibe amanye ama-hydrocarbon. Abacwaningi baphinde bathola ukuthi ama-catalyst powders aqukethe i-tungsten kuphela noma i-titanium enza kabi kakhulu; ngisho nalapho lezi zimpushana ezimbili zihlanganiswe ndawonye ngokomzimba, ukusebenza kwazo akuzange kufane ne-catalyst yokubambisana.

Ithimba lithemba ukuklama i-catalyst engcono kakhulu enenombolo ephezulu yokwenza inzuzo, kanye nempilo ende. "Sikholelwa ukuthi esikhathini esizayo esiseduze, izimboni zingasebenzisa indlela yethu yokukhiqiza ama-alkanes ebanga likadizili kanye nokusetshenziswa kwe-catalysis ngokuklama," kusho uSamantaray.