Influence of reduction temperature on the formation of intermetallic Pd2Ga phase and its catalytic activity in CO2 hydrogenation to methanol

The global warming and change in climatic conditions due to rising concentration of CO2 in atmosphere are the most important challenges of 21st century. Catalytic conversion of CO2 to methanol will not only check global warming but also provide an alternative source of fuel. The phase purity of solid catalysts has a considerable influence on the desired product selectivity. Reduction temperature is one of the most important parameters responsible for catalyst phase formation. Herein, the effect of a range of reduction temperatures between 100 and 600°C on the phase composition of Pd–Ga bimetallic catalyst and CO2 hydrogenation to methanol activity was investigated. X‐ray diffraction (XRD) analysis revealed the formation of different phases at different reduction temperatures. The variation in catalyst structure was also analyzed using field emission scanning electron microscope‐energy dispersive X‐ray spectroscopy (FESEM‐EDS), Brunaue–Emmett–Teller, H2 chemisorption, and transmission electron microscopy techniques. The influence of reduction temperature, pressure (1–25 bar), H2/CO2 ratio (3–9), and reaction temperature (150–250°C) on methanol and CO selectivity from CO2 hydrogenation at atmospheric pressure was also studied. © 2019 Society of Chemical Industry and John Wiley & Sons, Ltd.