Hydrogen production by steam reforming of liquefied natural gas (LNG) over mesoporous nickel-alumina aerogel catalyst

摘要

A mesoporous nickel-alumina aerogel catalyst (NiAE-SS) was prepared by a single-step sol-gel method and a subsequent CO_2 supercritical drying method for use in hydrogen production by steam reforming of liquefied natural gas (LNG). For comparison, a nickel catalyst supported on alumina aerogel (Ni/AE-IP) was also prepared by an impregnation method. The effect of preparation method of supported nickel catalysts on their physico-chemical properties and catalytic performance in the steam reforming of LNG was investigated. NiAE-SS catalyst retained superior textural properties compared to Ni/AE-IP catalyst. Nickel species were finely dispersed on the surface of both Ni/AE-IP and NiAE-SS catalysts through the formation of surface nickel aluminate phase. Although both Ni/AE-IP and NiAE-SS catalysts exhibited a stable catalytic performance, NiAE-SS catalyst showed a better catalytic performance than Ni/AE-IP catalyst in terms of LNG conversion and hydrogen yield. High nickel surface area, high nickel dispersion, and well-developed mesoporosity of NiAE-SS catalyst played an important role in enhancing the catalytic performance in the steam reforming of LNG. Uniformly distributed metallic nickel particles in the NiAE-SS catalyst were also responsible for its high catalytic performance.