Effect of Zirconium and Cerium Loadings on Aerogel Pd-Based Catalysts for Methane Combustion

• 作者: Abdelhamid Ghorbel Franck Dumeignil Khouloud Sadouki Mickael Capron Shemseddine Fessi Zouhaier Ksibi
• 来源期刊: 材料物理与化学进展(英文)
• 学科: 化学
• 关键词: Pd/(CexZr(1-x)O2)/SiO2 CATALYSTS METHANE Combustion Catalytic Activity
• 年，卷（期）: clwlyhxjzyw_2018,（3）
• 页码范围: 105-119
• 页数: 15页
• 分类号: O6

摘要

Aerogel Pd/(Ce0.33Zr0.66O2)SiO2 catalysts (CeZry) were prepared with variable Ce and Zr loadings (molar ratio Ce/Zr = 1/2) by combining sol-gel and impregnation methods. First, N2-physisorption was used to investigate the texture evolution. Then, H2-chimisorption and TEM were performed to study the effect on particle dispersion. After, TPR was used to determine the catalyst reducibility. Furthermore, XPS characterization was done to identify the palladium oxidation state and to evaluate the Pd-support interaction. Finally, the prepared catalysts were tested in methane combustion to assess their catalytic activity. The obtained results showed that, when the Zr and Ce loadings are varied between 0% and 8% and between 0% and 6% respectively, the BET surface area was increased from 615 to 744 m2/g, the porosity diameter from 45.7 to 83.6 Å, the Pd particle diameter from 5.2 to 7.0 nm, the CeO2 and ZrO2 particle size from 0 to 68 nm, the reduction temperature shift reached 16°C, the Pd binding energy shift attained 0.6 eV, but an optimum amounts of Zr (4 wt.%) and Ce (3 wt.%) are needed to maximize the PdO reducibility and to enhance the catalytic activity. In effect, 100% conversion of methane was reached at around 415°C on the CeZr4 catalyst.