Effect of Mg Contents on Catalytic Activity and Coke Formation of Mesoporous Ni/Mg-Aluminate Spinel Catalyst for Steam Methane Reforming

Hyunjoung Kim,Kyubock Lee,Jeong-Cheol Seo,Young-Hee Lee,Hongjin Lee

doi:10.3390/catal10080828

Abstract

Ni catalysts are most suitable for a steam methane reforming (SMR) reaction considering the activity and the cost, although coke formation remains the main problem. Here, Ni-based spinel catalysts with various Mg contents were developed through the synthesis of mesoporous Mg-aluminate supports by evaporation-induced self-assembly followed by Ni loading via incipient wetness impregnation. The mesoporous Ni/Mg-aluminate spinel catalysts showed high coke resistance under accelerated reaction conditions (0.0014 gcoke/gcat·h for Ni/Mg30, 0.0050 gcoke/gcat·h for a commercial catalyst). The coke resistance of the developed catalyst showed a clear trend: the higher the Mg content, the lower the coke deposition. The Ni catalysts with the lower Mg content showed a higher surface area and smaller Ni particle size, which originated from the difference of the sintering resistance and the exsolution of Ni particles. Despite these advantageous attributes of Ni catalysts, the coke resistance was higher for the catalysts with the higher Mg content while the catalytic activity was dependent on the reaction conditions. This reveals that the enhanced basicity of the catalyst could be the major parameter for the reduction of coke deposition in the SMR reaction.

Highlights

With the increasing concerns about air pollution and global warming, the development of a clean and alternative energy source to depleting fossil fuels has drawn great attention
We investigate the effect of the Mg content on the Ni crystal size, the pore structure, the basicity of the catalysts, and the resulting catalytic activity and coke resistance of the mesoporous
Our results show that catalysts with higher Mg content and basicity a more dominant effect than the effect of Ni particle size on suppressing coke formation

Summary

Introduction

With the increasing concerns about air pollution and global warming, the development of a clean and alternative energy source to depleting fossil fuels has drawn great attention. Considering the activity and the cost, Ni catalysts are regarded to be the most suitable, and the commercial SMR catalyst is Ni-based as well It is a highly matured process, coke formation is still a main problem for the SMR reaction, together with sintering, which leads to the deactivation of catalysts [7,8]. The main reason for reduced coke deposition is the improved basicity and dispersion of the Ni particles on the support, resulting in SMSI We investigate the effect of the Mg content on the Ni crystal size, the pore structure, the basicity of the catalysts, and the resulting catalytic activity and coke resistance of the mesoporous. Sintering resistance and the Ni particle formation by the exsolution, which has been less studied before

Discussion

This means that that well-defined and ordered mesopores of

Materials and Methods

Catalyst Characterization

Catalyst Activity Test of SMR

Conclusions