Nanosized Pt-containing Al2O3 as an efficient catalyst to avoid coking and sintering in steam reforming of glycerol†
The action of nanosized Pt-containing Al2O3 catalysts to avoid coking and sintering was studied in steam reforming of glycerol. The solids exhibited almost 100% conversion toward syngas produced at a suitable water to glycerol ratio. Depending on the promoter, a drastic drop in hydrogen yield was observed due to coking and sintering effects. Spent catalyst characterizations by Raman, HRTEM, XRD, TG and SEM-EDS as well as textural property techniques showed that coking, rather than sintering, was the main cause that determined the low hydrogen selectivity of nanosized Pt-containing Al2O3 with La2O3 or ZrO2. In contrast, coking did not cover the active sites of Pt-containing Al2O3 with MgO or CeO2. Thus, steam suppressed carbon deposition and improved the nanosized Pt/MgO–Al2O3 catalyst stability in the steam reforming of glycerol.