Thermodynamic possibility analysis of CH3COOH synthesis from CH4 and CO2

CH3COOH synthesis from CH4 and CO2 is a green and 100% atom-efficient reaction, but it is a thermodynamically unfavorable reaction. To better understand the thermodynamic limits and implementation methods of CH3COOH synthesis, thermodynamics is systematically studied by using HSC chemistry and density functional theory. It is found that the reaction is thermodynamically unfavorable in the homogeneous phase at 298 similar to 1000 K and 0.1 similar to 30 MPa, and the maximum equilibrium amount of CH3COOH is 6.0 x 10(-5)%. The bond strength between CH3COOH and the active site is the key factor affecting the thermodynamics of this reaction in the heterogeneous phase. If the bond strength between CH3COOH and the active site is weak, H-2 can break the thermodynamic bottleneck, of which the mechanical work of the pressure (H-2 (supplied)) overcomes the thermodynamic barrier. On the contrary, H2O can break the thermodynamic bottleneck due to the competition adsorption between H2O and CH3COOH.