等离子体与催化材料协同作用CO₂甲烷化反应为CO₂再利用提供了可能, 但催化材料的制备方法对其结构和性能有重要影响。本研究以等体积浸渍法制备的Ru/γ-Al₂O₃为催化材料前驱体, 分别采取H₂大气压冷等离子体还原和H₂热还原方法制备Ru/γ-Al₂O₃-P和Ru/γ-Al₂O₃-T催化材料。考察两种方法制备Ru/γ-Al₂O₃催化材料与大气压冷等离子体共同作用下CO₂甲烷化反应中的催化活性, 并采用不同测试方法研究制备方法对Ru/γ-Al₂O₃结构的影响, 分析影响Ru/γ-Al₂O₃催化活性的结构因素, 进而探究了Ru/γ-Al₂O₃-P和Ru/γ-Al₂O₃-T催化材料的制备机理。研究结果表明: 载体γ-Al₂O₃与大气压等离子体共同作用下CO₂转化率为24.8%, 主要产物是CO; Ru/γ-Al₂O₃与大气压等离子体共同作用下的主要产物是甲烷。Ru/γ-Al₂O₃-T和Ru/γ-Al₂O₃-P催化材料的CO₂转化率分别为66.9%和77.3%。Ru/γ-Al₂O₃-P较高的催化活性源于其表面Ru还原程度高、Ru/Al原子比高以及Ru单质在载体γ-Al₂O₃上分散性较好且粒径较小, 说明采用大气压H₂冷等离子体技术可制备高活性的负载型金属催化材料。

The synergy of plasma and catalytic materials for CO₂ methanation provides the possibility for CO₂ reuse. The preparation method of catalytic materials plays an important role on their structure and performance. In this work, Ru/γ-Al₂O₃-P and Ru/γ-Al₂O₃-T catalytic materials were prepared by atmospheric-pressure H₂ plasma reduction and H₂ thermal reduction, respectively, using Ru/γ-Al₂O₃ precursor prepared by incipient wetness impregnation. The catalytic activity of Ru/γ-Al₂O₃ prepared by different methods was evaluated during atmospheric-pressure plasma reduction for CO₂ methanation reaction. Different techniques were used to investigate the effect of preparation methods on the structure of Ru/γ-Al₂O₃, analyze the influences of structural factor on the catalytic activity of Ru/γ-Al₂O₃, and discuss the preparation mechanism of Ru/γ-Al₂O₃-P and Ru/γ-Al₂O₃-T. The results show that the CO₂ conversion of γ-Al₂O₃ support is 24.8% under the combination of atmospheric-pressure plasma, and the main product is CO. However, the main CO₂ catalytic product of Ru/γ-Al₂O₃ is methane under the combination of atmospheric-pressure plasma. CO₂ conversion over Ru/γ-Al₂O₃-P is 77.3%, which is higher than that over Ru/γ-Al₂O₃-T (69.9%). Higher catalytic activity of Ru/γ-Al₂O₃-P is ascribed to the higher metallic Ru ratio and Ru/Al atomic ratio, as well as the smaller and higher dispersion of Ru nanoparticles. This work proves that highly active supported metal catalytic materials can be prepared by atmospheric-pressure H₂ plasma.