Significantly Improved Catalytic Performance of Ni-Based MgO Catalyst in Steam Reforming of Phenol by Inducing Mesostructure

Xiaoxuan Yang,Yajing Wang,Yuhe Wang

doi:10.3390/catal5041721

Abstract

A Ni/meso-MgO catalyst with high surface area and small Ni nanoparticles was synthesized and investigated for hydrogen production by steam reforming of phenol for the first time. Compared to conventional Ni/MgO, the Ni/meso-MgO catalyst showed higher catalytic activity and stability. X-ray Diffraction, N2 adsorption, hydrogen temperature programmed reduction, transmission electron microscopy and thermal gravimetry results indicated that the Ni/meso-MgO catalyst had higher surface area than Ni/MgO and Ni particles of Ni/meso-MgO were narrowly distributed in the range of 5~6 nm with an average size of 5.3 nm, while Ni particles of Ni/MgO were in the range of 6~10 nm with an average size of 7.92 nm. The small and uniform Ni nanoparticles in Ni/meso-MgO were attributed to the high surface area and the confinement effect of the mesoporous structure of meso-MgO, which could effectively limit the growth of the active metal and stabilize Ni particles during the procedure of NiO reduction. The mesoporous structure of Ni/meso-MgO also played an important role in suppressing Ni nanoparticle sintering and carbon deposition during the steam reforming of phenol reaction.

Highlights

Hydrogen produced from renewable resources, e.g., biomass, without net contribution to CO2 emissions, is one of the most promising clean fuels [1]
Note that the X-ray diffraction (XRD) diffraction peak intensity of the fresh NiO/meso-MgO solid solution is lower than that of meso-MgO, which was caused by the decline of the order of mesoporous structure when NiO loaded on the pore wall of meso-MgO
The similar decrease in the diffraction peak intensity was observed over the used Ni/meso-MgO catalyst compared to the fresh one, suggesting that mesoporous structure partially degraded

Summary

Introduction

Hydrogen produced from renewable resources, e.g., biomass, without net contribution to CO2 emissions, is one of the most promising clean fuels [1]. Biomass gasification for hydrogen production is a fast developing technology [2]. Products usually formed during biomass gasification, are aromatic hydrocarbons containing about 5.0 wt. Ni-based catalysts are the extensively studied catalysts for steam reforming of organic hydrocarbons due to their low cost and initial high catalytic activity [6,7]. Efforts have been made for Ni-based catalysts with resistance to Ni sintering and coke deposition by reducing the particle size of active metal, forming inactive carbon [9,10], and employing strong Lewis bases as catalyst supports [11]. Some encouraging results have been obtained, developing Ni-based catalysts with both high catalytic activity and stability for steam reforming of organic hydrocarbons still remains a challenge

Methods

Results

Conclusion