Synthesis of highly active nano-sized (1 wt.% Pt/CeO2) catalyst for water gas shift reaction in medium temperature application

A simultaneous precipitation/digestion method has been developed to precipitate a crystalline cerium (III) carbonate (Ce2(CO3)3·8H2O) by a controlled reaction between aqueous solutions of Ce(NO3)3·6H2O and K2CO3 at room temperature. The nano-sized CeO2 supports with crystallite size of 8.0 nm and high surface area of 131.6 m2/g were successfully prepared through a decomposition of a cerium (III) carbonate at 400 °C for 4 h. The digestion time was optimized to get highly active 1 wt.% Pt/CeO2 catalyst for the water gas shift (WGS) reaction. 1 wt.% Pt/CeO2 catalyst exhibited the highest CO conversion (82%) and 100% selectivity to CO2 at 320 °C at very high gas hourly space velocity (GHSV) of 45,625 h−1 if an optimized digestion time of 4 h was used for the synthesis of cerium (III) carbonate.

Graphical abstractA simple simultaneous precipitation/digestion method has been developed to precipitate a crystalline cerium (III) carbonate (Ce2(CO3)3·8H2O) by a controlled reaction between aqueous solutions of Ce(NO3)3·6H2O and K2CO3 at room temperature. The nano-sized CeO2 supports with crystallite size of 8.0 nm and high surface area of 131.6 m2/g were successfully prepared through a decomposition of a cerium (III) carbonate at 400 °C for 4 h. The digestion time was optimized to get highly active 1 wt.% Pt/CeO2 catalyst for the water gas shift (WGS) reaction. 1 wt.% Pt/CeO2 catalyst exhibited the highest CO conversion (82%) and 100% selectivity to CO2 at 320 °C at very high gas hourly space velocity (GHSV) of 45,625 h−1 if an optimized digestion time of 4 h was used for the synthesis of cerium (III) carbonate.Figure optionsDownload full-size imageDownload high-quality image (79 K)Download as PowerPoint slideHighlights► A simultaneous precipitation/digestion method has been developed to obtain a crystalline Ce2(CO3)3·8H2O as a precursor of nano-sized CeO2 support. ► An optimum digestion time for the synthesis of Ce2(CO3)3·8H2O has been found to be 4 h. ► 1 wt.% Pt/CeO2 catalyst exhibited relatively stable activity even at the GHSV of 45,625 h−1 at 320 °C in WGS.