Pt/Al2O3和Pt/CeO2/Al2O3催化甲烷部分氧化制合成气反应

研究了Pt/Al₂O₃和Pt/CeO₂/Al₂O₃对甲烷部分氧化制合成气反应的催化活性,发现Pt/CeO₂/Al₂O₃显示了更高的甲烷转化率和合成气选择性.用H₂-TPR、H₂-TPD、SEM-EDX和XRD等技术对催化剂进行了表征.CeO₂和Pt相互作用促进Pt在催化剂表面的分散,抑制Pt在催化剂表面的迁移;降低了催化剂的燃烧活性,提高了催化剂的部分氧化活性和选择性,可避免因催化剂床层局部温度过高而导致催化剂活性下降或失活,提高了催化剂的稳定性.同时,CeO₂通过促进水汽变换反应使反应体系迅速达到平衡,提高了催化剂对H₂的选择性.

Partial Oxidation of Methane to Syngas over Pt/Al2O3 and Pt/CeO2/Al2O3

The catalytic oxidation of methane to syngas has been carried out over Pt/Al 2O 3 and Pt/CeO 2/Al 2O 3. It was found that the catalysts with ceria exhibit a higher activity and selectivity than those without ceria. The catalysts were characterized by means of TPR, TPD, SEM EDX and XRD. There is a strong interaction between ceria and platinum under the reaction condition, which increase the dispersion of platinum over catalysts, preventing the sinter of the Pt particles. As a result of the synergistic effect between Pt and ceria, the activity of Pt/Al 2O 3 for combustion reaction was suppressed, the activity and selectivity for partial oxidation were improved greatly. Another role of ceria in the catalyst is the enhancing of the WGSR, which leads to the increase of the selectivity of catalyst for hydrogen and accelerating the equilibrium of the reaction.