Syngas Production via Steam鈥揅O2 Dual Reforming of Methane over LA-Ni/ZrO2 Catalyst Prepared by l-Arginine Ligand-Assisted Strategy: Enhanced Activity and Stability

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• 作者：Weizuo Li ; Zhongkui Zhao ; Fanshu Ding ; Xinwen Guo ; Guiru Wang
• 刊名：ACS Sustainable Chemistry & Engineering
• 出版年：2015
• 出版时间：December 7, 2015
• 年：2015
• 卷：3
• 期：12
• 页码：3461-3476
• 全文大小：983K
• ISSN：2168-0485

文摘

A highly dispersed supported nickel catalyst (LA-Ni/ZrO₂), synthesized by a facile l-arginine ligand-assisted incipient wetness impregnation (LA-IWI) approach, demonstrates much superior catalytic activity and exceptional stability for steam鈥揅O₂ dual reforming of methane in comparison with the classical Ni/ZrO₂ catalyst by the IWI method. The origin of the enhanced activity and stability of the developed LA-Ni/ZrO₂ catalyst as well as the role of the Ni鈥搟(l-Arg)} complex as the Ni precursor is revealed by employing diverse characterization techniques including X-ray diffraction (XRD), N₂ adsorption (BET), transmission electron microscopy (TEM), H₂ temperature-programmed reduction (H₂-TPR), Fourier transform infrared spectroscopy (FT-IR), Raman spectroscopy (Raman), CO chemisorption, temperature-programmed hydrogenation (TPH), and thermogravimetric analysis (TGA). The superior catalytic activity of the developed LA-Ni/ZrO₂ catalyst to the classical Ni/ZrO₂ can be ascribed to the higher Ni dispersion, intensified Ni鈥搒upport interaction, the enlarged oxygen vacancies, as well as the increased t-ZrO₂ content and enhanced reducibility of NiO led by oxygen vacancies. More interestingly, although a larger amount of coke depositing on the spent LA-Ni/ZrO₂ catalyst in comparison with that on the spent Ni/ZrO₂ can be observed by TGA and TPH measurement, the developed LA-Ni/ZrO₂ illustrates much higher catalytic stability to Ni/ZrO₂, ascribed to the superior thermal sintering resistance of Ni nanoparticles and the different coke morphologies confirmed by TEM images led by intensified interaction of Ni and the ZrO₂ support. The much superior catalytic activity and stability of the developed LA-Ni/ZrO₂ catalyst endows it to be a promising candidate for syngas production with diverse H₂/CO ratios via steam鈥揅O₂ dual reforming of methane.