Carbon dioxide fixation into chemicals (methyl formate) at high yields by surface coupling over a Pd/Cu/ZnO nanocatalyst

Chemical fixation of CO2 has recently attracted attention as a possible way to manufacture useful chemicals. Here, we demonstrate a one-step catalytic fixation of CO2 to methyl formate (MF) in liquid phase under mild industrial applicable conditions by using a new concept of coupling surface formate species formed from CO2 on solid catalyst with excess methanol in hydrogen to form the MF, and the quantity of the product is found to greatly exceed the surface coverage of the catalyst by > 45-fold. As a result, we report, for the first time, that the optimum Pd/Cu/ZnO/alumina nanocatalyst prepared from simple co-precipitation is capable of activating gaseous CO2 to condensable MF at high yields (> 20%) with excellent selectivity (> 96%). The present study also offers directions to rationally design and optimize the required catalyst, reactor, and experimental conditions for this new reaction.