Isobutane dehydrogenation over unimodal porous catalyst (part 1) effect of pore distribution of S-Pt/ZnO/Al_2O_3 catalyst on dehydrogenation,activity,selectivity,ad deactivation rate

摘要

The unimodal porous #gamma#-alumins as carriers were applied to the Sn-Pt/ZnO/Al_2O_3 catalyst system for dehdyrogenation of lower paraffins.Physical properties such as surface area,average pore diameter,pore volume of the unimodal porous alumina carriers can be mostly reflected in the resulted catalysts.The unimodal porous catalysts exhibit excellent activities and selectivities for isobutane dehydrogenation in comparison with those of the non-unimodal porous catalyst which is prepared from #gamma#-alumina carrier with broad pore distriubtion.Furthermore,the influence of pore diameter on such catalyti cperformamances as activity,selectivity,deactivation rate are also unveiled with the unimodalporous catalysts having specific pore diameters.It is found that pore diameter of the catalyst affects but slightly the initial conversion of isobutane,but affects more extensively the degree of selectvity and deactivation rate,especially in the deactivation rate in which catalyst of pore diameter shows 1/3 of the deactivation rate compaed with that of pore diameter.Catalyst pore distribution and pore diameter afect dehydrogenation and the aplication of the unimodal porous alumina carrier makesit possible toprepae unimodal porous catalysts.ZnO is considered to be well dispersed on the unimodal porous catalyst despite large amount of impregnation.