Hydrogen production by steam reforming of liquefied natural gas (LNG) over trimethylbenzene-assisted ordered mesoporous nickel–alumina catalyst

Abstract

A trimethylbenzene (TMB)-assisted ordered mesoporous nickel–alumina catalyst (denoted as TNA) was prepared by a single-step evaporation-induced self-assembly (EISA) method, and it was applied to the hydrogen production by steam reforming of liquefied natural gas (LNG). For comparison, an ordered mesoporous nickel–alumina catalyst (denoted as NA) was also prepared by a single-step EISA method in the absence of TMB. Pore volume and average pore diameter of TNA catalyst were larger than those of NA catalyst due to structural modification caused by TMB addition in the preparation of TNA catalyst. In addition, TNA catalyst showed less ordered mesoporous array than NA catalyst. Both NA and TNA catalysts exhibited diffraction patterns corresponding to nickel aluminate phase, and they retained surface nickel aluminate phase with high stability and reducibility. Crystallite size of metallic nickel in the reduced TNA catalyst was smaller than that in the reduced NA catalyst due to strong nickel–alumina interaction of surface nickel aluminate phase over TNA catalyst. In the hydrogen production by steam reforming of LNG, TNA catalyst with small crystallite size of metallic nickel showed a better catalytic performance than NA catalyst in terms of LNG conversion and hydrogen yield. Furthermore, steam reforming reaction rather than water–gas shift reaction favorably occurred over TNA catalyst.