Syngas to lower olefins over bulk Mo 2 N catalysts prepared with citric acid

Herein, we report on the activity and selectivity of bulk γ‐Mo 2 N catalysts for Fischer–Tropsch lower olefin (FTO) synthesis. An increase in surface area and a decrease in crystallite size were observed for γ‐Mo 2 N catalysts prepared with the increased molar amount of citric acid (CA), used as a chelating agent during the catalyst synthesis. The reaction products were mainly C 2 –C 3 hydrocarbons in the temperature range of 230–300°C at 2 MPa with a reactant feed composition of CO:H 2 :Ar = 42.7:34.6:20.8 and a gas hourly space velocity (GHSV) of 1.3 mol/(g cat .h). The catalytic activity of the γ‐Mo 2 N catalysts increased with increased CA:Mo molar ratio and with temperature. However, the hydrogenation activity of the catalysts also increased, resulting in increased selectivity to paraffins. Selectivity to olefins prefers low CA:Mo, that is, low surface area and large crystallite size of γ‐Mo 2 N. The γ‐Mo 2 N catalyst prepared with a CA:Mo ratio of 1 had 56.4 C atom% C 2+ hydrocarbon selectivity, 62.4% of which was olefin with 37.8 C atom% selectivity to propylene at 275°C.