γ-Mo2N/C催化剂的合成及其甲酸脱氢性能研究OACSTPCD

Formic acid(FA)has received much attention due to its high hydrogen content(4.4％),easy H2 production and synthesis from small platform compounds.γ-Mo2N/C is very selective for the decomposition of FA along the H2 and CO2 pathways,generating very little CO and showing high application value.In this study,γ-Mo2N/C catalysts were prepared using aqueous p-phenylenediamine and ammonium molybdate solutions as precursors,and their FA decomposition performance was evaluated in-situ.The adsorption conformation of FA on the crystalline surface of γ-Mo2N(200)was calculated by DFT,and on this basis,the catalyst performance and the decomposition mechanism of FA on its surface were investigated.The results showed that γ-Mo2N/C exhibited very high catalytic activity at low temperatures and that improving the dispersion of γ-Mo2N on the C carrier was effective in improving the FA conversion.The best catalytic performance was achieved at a molar ratio of 4∶1 between p-phenylenediamine and ammonium molybdate,and the catalyst showed stable performance and high H2 selectivity(N2 40 mL/min,CO＜5.0×10-5)in the FA decomposition experiments at 160 ℃ and 100 h.DFT calculations showed that the H atom of the O-H bond in FA was more likely to bind to the N atom on the crystalline surface of γ-Mo2N/C(200),while the O atom of the C=O bond are more likely to bind to Mo atoms on the γ-Mo2N/C(200)crystal plane.The above results help to clarify the mechanism of FA decomposition under the action of γ-Mo2N/C and show the potential application of the non-precious metal catalyst γ-Mo2N/C in the decomposition of FA for H2 production.