In order to lay a foundation for effective regeneration of P W heteropoly acid catalyst supported on SiO 2 aged in the alkylation of isobutane with butene, the molecular structure and physicochemical properties of cok...In order to lay a foundation for effective regeneration of P W heteropoly acid catalyst supported on SiO 2 aged in the alkylation of isobutane with butene, the molecular structure and physicochemical properties of coke precursor deposited on the surface of solid acid alkylation catalyst are clearly recognized and identified by means of various characterization approaches, including IR, NMR, GC MS and GC. According to the characterization results, the coke precursors are mainly made up of long chain saturated hydrocarbons and small amount of polynucleo aromatics. The coke precursors deposit on the catalysts do not block the pores of the catalysts, but deposited on the acid centres of catalyst. It causes that the acid strength of active centres of the catalyst descends, and selectivity for alkylation becomes worse. It is found that the species of coke precursor consist of C 13 ～C 21 paraffin. The results obtained in the project are different entirely from that other researchers gained before. It will be of benefit to investigate and find out new regeneration methods of solid acid alkylation catalyst.展开更多
A series of Co-imbedded zeolite-based catalysts were synthesized following a facile solvent-free grinding route.The catalytic performance for direct syngas conversion to gasoline range hydrocarbons was compared with t...A series of Co-imbedded zeolite-based catalysts were synthesized following a facile solvent-free grinding route.The catalytic performance for direct syngas conversion to gasoline range hydrocarbons was compared with their counterpart Co-impregnated zeolite-based catalysts.Successful transformation of solid raw materials to targeted zeolite was confirmed by XRD,SEM,STEM,and N2 physisorption analysis.An in-depth study of acidic strength and acidic site distribution was conducted by NH3-TPD and Py-IR spectroscopy.Acidic strength showed a pivotal role in defining product range.Co@S1,with the weakest acidic strength of silicalite-1 among three types of zeolites,evaded over-cracking of product and exhibited the highest gasoline and isoparaffin selectivity(≈70%and 30.7%,respectively).Moreover,the solvent-free raw material grinding route for zeolite synthesis accompanies several advantages like the elimination of production of wastewater,high product yield within confined crystallization space,and elimination of safety concerns regarding high pressure due to the absence of the solvent.Facileness and easiness of the solvent-free synthesis route together with promising catalytic performance strongly support its application on the industrial scale.展开更多
文摘In order to lay a foundation for effective regeneration of P W heteropoly acid catalyst supported on SiO 2 aged in the alkylation of isobutane with butene, the molecular structure and physicochemical properties of coke precursor deposited on the surface of solid acid alkylation catalyst are clearly recognized and identified by means of various characterization approaches, including IR, NMR, GC MS and GC. According to the characterization results, the coke precursors are mainly made up of long chain saturated hydrocarbons and small amount of polynucleo aromatics. The coke precursors deposit on the catalysts do not block the pores of the catalysts, but deposited on the acid centres of catalyst. It causes that the acid strength of active centres of the catalyst descends, and selectivity for alkylation becomes worse. It is found that the species of coke precursor consist of C 13 ～C 21 paraffin. The results obtained in the project are different entirely from that other researchers gained before. It will be of benefit to investigate and find out new regeneration methods of solid acid alkylation catalyst.
基金the financial support from the Zhejiang Province Natural Science Foundation(LY19B060001)the Foundation of State Key Laboratory of High-efficiency Utilization of Coal and Green Chemical Engineering(2018-K25)the Foundation of Zhejiang University of Science and Technology(2019QN18,2019QN23)~~
文摘A series of Co-imbedded zeolite-based catalysts were synthesized following a facile solvent-free grinding route.The catalytic performance for direct syngas conversion to gasoline range hydrocarbons was compared with their counterpart Co-impregnated zeolite-based catalysts.Successful transformation of solid raw materials to targeted zeolite was confirmed by XRD,SEM,STEM,and N2 physisorption analysis.An in-depth study of acidic strength and acidic site distribution was conducted by NH3-TPD and Py-IR spectroscopy.Acidic strength showed a pivotal role in defining product range.Co@S1,with the weakest acidic strength of silicalite-1 among three types of zeolites,evaded over-cracking of product and exhibited the highest gasoline and isoparaffin selectivity(≈70%and 30.7%,respectively).Moreover,the solvent-free raw material grinding route for zeolite synthesis accompanies several advantages like the elimination of production of wastewater,high product yield within confined crystallization space,and elimination of safety concerns regarding high pressure due to the absence of the solvent.Facileness and easiness of the solvent-free synthesis route together with promising catalytic performance strongly support its application on the industrial scale.
