Activity of bimetallic PdIn/CeO2 catalysts tuned by thermal reduction for improving methanol synthesis via CO2 hydrogenation

Synergistic Pd–In 2 O 3 catalysts are promising candidates for producing methanol via CO 2 hydrogenation, and the metal phases in them can be tuned by thermal reduction treatment affecting the catalytic activity significantly. This work presents a comprehensive investigation to gain an insight into the effect of thermal reduction temperature on the variation and interaction of Pd and In 2 O 3 phases supported on CeO 2 (viz., PdIn/CeO 2 ) and their correlations with CO 2 hydrogenation toward methanol synthesis. The findings show that Pd/In-rich PdIn alloys and In 2 O 3 with relatively strong interaction are key phases (by reducing the PdIn/CeO 2 at 300°C) for promoting methanol formation, leading to a high selectivity to methanol at 78.9% and space–time yield (STY) of 3.6 g CH3OH g PdIn −1 h −1 . A further increase in reduction temperature (from 300 to 500°C) promoted the formation of homogenized PdIn intermetallic alloys with significantly poor ability for H 2 dissociation and CO 2 activation, and hence poor methanol yield.