负载型钯催化剂上生物质气化气催化燃烧

采用浸渍法制备了Pd/Al2O3、Pd/Ce/Al2O3、Pd/Mn/Al2O3、Pd/La/Al2O3四种催化剂。并借助XRD、BET对催化剂相结构、比表面积、孔结构进行了表征,在固定床反应器上考察了四种催化剂对CO、H2和CH4的催化燃烧性能。结果表明,随着La、Ce、Mn离子的引入使得催化剂的比表面积和孔容积不断降低;添加助剂Ce可以提高催化剂活性和热稳定性,助剂La可以提高催化剂的抗烧结能力,而助剂Mn在低温时可以提高催化剂活性,但并不能抑制催化剂的高温钝化。CO和H2的起燃顺序随催化剂的不同而不同,但四种催化剂对CO和H2的催化燃烧活性接近,均可以在低温条件下迅速燃烧,同时其燃烧特征温度明显低于CH4。

Catalytic combustion of gas from biomass gasification over supported palladium catalysts

Pd/Al₂O₃, Pd/Ce/Al₂O₃, Pd/Mn/Al₂O₃ and Pd/La/Al₂O₃ catalysts were prepared by the impregnation method and characterized by BET and XRD analysis. The performance of catalysts for CO, H₂ and CH₄ combustion were explored in a fixed bed reactor. The results show that doping of La, Ce or Mn to catalyst can lead to the decrease of specific surface area and pore volume. And the doping of Ce can obviously improve the catalytic activity and thermal stability, while the doping of La don't improve catalytic activity, but enhance the thermal stability of catalysts under high-temperature calcinations. The doping of transition metal Mn leads to an enhancement of the combustion activity, whereas can accelerate the transition of γ-Al₂O₃ to α-Al₂O₃. It is also found that the ignition sequence of CO and H₂ varies for different catalysts, but all catalysts show similar activity for CO and H₂ combustion that can quickly conduct at low temperature, and the combustion characteristic temperature of them is far below that of CH₄.