Optimization of a highly active nano-sized Pt/CeO2 catalyst via Ce(OH)CO3 for the water-gas shift reaction

Crystalline cerium hydroxy carbonate (CHC: Ce(OH)CO3) was prepared by a novel precipitation/digestion method at room temperature in air. The nano-sized CeO2 supports were obtained by the thermal decomposition of CHC and the Pt/CeO2 catalysts were prepared by an incipient wetness impregnation method. The pre-calcination temperature and aging time were optimized to obtain a highly active Pt/CeO2 catalyst for the water gas shift reaction (WGS). The Pt/CeO2 catalyst exhibited the highest CO conversion (82%) and the lowest activation energy (55 kJ/mol) at a very high gas hourly space velocity (GHSV) of 45,515 h−1 when the optimized synthesis parameter (pre-calcined temperature = 400 °C and aging time = 4 h) was used in the synthesis of CeO2. This is mainly due to the high BET surface area, nano-sized CeO2, and intimate interaction between Pt and CeO2.