N,P掺杂型C@Mo_2C催化剂的制备及其催化CO_2加氢反应研究

以三聚氰胺苯甲酸盐为碳源和氮源、以三聚氰胺磷钼酸盐为钼源、磷源和氮源,采用程序升温的方法制备了系列N,P掺杂型C@Mo_2C催化剂。采用XRD、SEM、TEM和XPS等对催化剂的结构、形貌和表面特性进行了表征,研究了三聚氰胺苯甲酸盐中n(三聚氰胺)/n(苯甲酸)、前驱体中n(C)/n(Mo)等因素对所制备催化剂的结构及其在二氧化碳加氢反应中催化性能的影响。在反应温度为220℃、反应压力为3.0 MPa、空速为3 600 m L/(g·h)的条件下,在N,P掺杂型C@Mo_2C的催化作用下,CO_2转化率可以达到12.2%,此时产物中CH_3OH的选择性达到52.2%。

Synthesis of N,P-doped C@Mo2C catalyst and its application in CO2 hydrogenation

The N,P-doped C@Mo₂C catalysts were prepared using melamine benzoate as the source of nitrogen and carbon, melamine phosphomolybdate as the source of phosphorus, nitrogen and molybdenum, respectively. The surface structures of the prepared catalysts were characterized by XRD, SEM, TEM and XPS. The effects of the ratio of benzoic acid to melamine in melamine benzoate and n(C)/n(Mo) of the precursor on the catalysts were investigated. The activity of the catalysts was evaluated by using CO₂ hydrogenation as a model reaction in a fixed-bed reactor, in which a mixed gas of CO₂/H₂ (V_H2:V_CO2=3:1) was used as the feed gas, and it was found that the N,P-doped C@Mo₂C showed a good catalytic performance with CO₂ conversion of 12.2% and methanol selectivity of 52.2% under the optimal reaction conditions (reaction temperature 220℃, reaction pressure 3.0 MPa, space velocity 3 600 mL/(g·h).