Mild and selective hydrogenation of CO2 into formic acid over electron-rich MoC nanocatalysts.

ABSTRACT

The direct hydrogenation of CO2 using H2 gas is a one-stone-two-birds route to produce highly value-added hydrocarbon compounds and to lower the CO2 level in the atmosphere. However, the transformation of CO2 and H2 into hydrocarbons has always been a great challenge while ensuring both the activity and selectivity over abundant-element-based nanocatalysts. In this work, we designed a Schottky heterojunction composed of electron-rich MoC nanoparticles embedded inside an optimized nitrogen-doped carbon support (MoC@NC) as the first example of noble-metal-free heterogeneous catalysts to boost the activity of and specific selectivity for CO2 hydrogenation to formic acid (FA) in liquid phase under mild conditions (2 MPa pressure and 70 °C). The MoC@NC catalyst with a high turnover frequency (TOF) of 8.20 molFA molMoC-1 h-1 at 140 °C and an excellent reusability are more favorable for real applications.