I-catalyst esebenza kakhulu eguqula igesi yepropane ibe yi-hydrocarbons enzima iphuhliswe yi-Saudi Arabia's King Abdullah University of Science and Technology. (KAUST) abaphandi. Ikhawulezisa kakhulu ukusabela kweekhemikhali ezaziwa njenge-alkane metathesis, enokusetyenziswa ukuvelisa izibaso ezingamanzi.

I-catalyst ilungisa kwakhona ipropane, equlethe iiathom zekhabhoni ezintathu, kwezinye iiathomu, ezifana ne-butane (equlethe iikhabhoni ezine), i-pentane (eneekhabhoni ezintlanu) kunye ne-ethane (eneekhabhoni ezimbini). "Injongo yethu kukuguqula i-alkanes ephantsi ye-molecular weight alkanes exabisekileyo ye-diesel-range alkanes," watsho uManoja Samantaray ovela kwi-KAUST Catalysis Centre.

Embindini we-catalyst kukho iikhompawundi zeentsimbi ezimbini, i-titanium kunye ne-tungsten, ezibotshelelwe kumphezulu we-silica kusetyenziswa iiathom zeoksijini. Isicwangciso esisetyenzisiweyo sasiyi-catalysis by design. Uphononongo lwangaphambili lubonise ukuba ii-catalysts ze-monometallic bezibandakanyeka kwimisebenzi emibini: i-alkane ukuya kwi-olefin kunye ne-olefin metathesis. I-Titanium yakhethwa ngenxa yokukwazi ukwenza i-CH bond yeparafini ukuba iguqule ibe yi-olefins, kwaye i-tungsten yakhethwa ngenxa yomsebenzi wayo ophezulu we-olefin metathesis.

Ukudala i-catalyst, iqela lifudumeza i-silica ukususa amanzi amaninzi ngokusemandleni kwaye emva koko yongeza i-hexamethyl tungsten kunye ne-tetraneopentyl titanium, yenza i-powder-yellow yellow. Abaphandi baphonononge i-catalyst besebenzisa i-nuclear magnetic resonance (NMR) spectroscopy ukubonisa ukuba i-tungsten kunye ne-athomu ye-titanium zilele ngokusondeleleneyo kumphezulu we-silica, mhlawumbi isondele njenge-≈0.5 nanometres.

Abaphandi, bekhokelwa nguMlawuli weziko uJean-Marie Basset, emva koko bavavanya i-catalyst ngokuyifudumeza kwi-150 ° C kunye nepropane iintsuku ezintathu. Emva kokuphucula iimeko zokusabela-umzekelo, ngokuvumela i-propane ukuba ihambe ngokuqhubekayo phezu kwe-catalyst-bafumene ukuba iimveliso eziphambili ze-reaction yi-ethane kunye ne-butane kwaye iperi nganye ye-tungsten kunye ne-athomu ye-titanium inokubangela umyinge wemijikelezo ye-10,000 ngaphambili. ukulahlekelwa ngumsebenzi wabo. Eli “nani lembuyekezo” lelona liphezulu kwezakha zaxelwa kwi-propane metathesis reaction.

Le mpumelelo ye-catalysis ngokuyila, abaphandi bacebisa, ngenxa yesiphumo esilindelekileyo sentsebenziswano phakathi kwezi zimbi zimbini. Okokuqala, i-athomu ye-titanium isusa iiathom ze-hydrogen kwi-propane ukuze zenze i-propene kwaye i-athomu ye-tungsten engummelwane iqhawula i-propene evulekileyo kwibhondi yayo ye-carbon-carbon kabini, idala amaqhekeza anokuthi adibane kwezinye ii-hydrocarbons. Abaphandi baye bafumanisa ukuba i-catalyst powders equkethe kuphela i-tungsten okanye i-titanium yenziwe kakubi kakhulu; nangona ezi zimbini zomgubo zixutywe kunye, ukusebenza kwazo akuzange kuhambelane ne-catalyst yentsebenziswano.

Iqela linethemba lokuyila i-catalyst engcono kunye nenani eliphezulu le-turnover, kunye nobomi obude. "Sikholelwa ukuba kwikamva elingekude, ishishini lingasebenzisa indlela yethu yokuvelisa i-alkanes yoluhlu lwe-diesel kunye ne-catalysis ngokuyila," utshilo uSamantaray.