Effect of Supports and Promoters on the Performance of Ni‐Based Catalysts in Ethanol Steam Reforming

Abstract

Ethanol steam reforming (ESR) is one of the potential processes to convert ethanol into valuable products. Hydrogen produced from ESR is considered as green energy for the future and can be an excellent alternative to fossil fuels with the aim of mitigating the greenhouse gas effect. The ESR process has been well studied, using transition metals as catalysts coupled with both acidic and basic oxides as supports. Among various reported transition metals, Ni is an inexpensive material with activity comparable to that of noble metals, showing promising ethanol conversion and hydrogen yields. Additionally, different promoters and supports were utilized to enhance the hydrogen yield and the catalyst stability. This review summarizes and discusses the influences of the supports and promoters of Ni‐based catalysts on the ESR process.

Effect of the incorporation of reducibility promoters (Cu, Ce, Ag) in Co/ CaSBA ‐15 catalysts for acetic acid steam reforming

“…This explains why the selection of the support material is a key factor in this kind of processes. 32,33 SBA-15 silica has been reported as an adequate support to improve the dispersion of the metallic phase, since metal particles can diffuse through the channels of its mesoporous structure allowing greater interaction between the support and the active phase, hindering metal sintering. [34][35][36] The presence of Ca in the catalyst structure may lead to better catalytic performance, since this material is considered an efficient solid sorbent because of its promising chemical and thermodynamic properties.…”

“…Both metals tend to form coke deposits and sinter throughout the steam reforming process. This explains why the selection of the support material is a key factor in this kind of processes 32,33 . SBA‐15 silica has been reported as an adequate support to improve the dispersion of the metallic phase, since metal particles can diffuse through the channels of its mesoporous structure allowing greater interaction between the support and the active phase, hindering metal sintering 34‐36 …”

Chemical Looping Steam Methane Reforming via Ni‐ferrite Supported on Cerium and Zirconium Oxides

“…Phung et al [20] used Ni-based catalysis on the ethanol steam reforming process. They found that Ni enhanced ethanol conversion and hydrogen production.…”

Ethanol Steam Reforming for Hydrogen Production Over Hierarchical Macroporous Mesoporous SBA-15 Supported Nickel Nanoparticles

“…Low-cost-earth-abundant base metals, such as Ni, are commonly the active site of choice for ethanol steam reforming (ESR) due to superior economics [4], but routinely suffer on-stream deactivation by coking and sintering [5,6]. Fine-tuning of reaction conditions can inhibit carbon deposition, through increased process temperature or addition of O 2 to drive coke oxidation, but at the expense of increased potential for active site sintering, operating costs, or active site oxidation [7].…”

“…Alternatively, modifying the chemical nature of the support structure provides a second strategy to address coke accumulation. Alkali metal or alkali earth metal promotors switch-off ethanol dehydration and ethylene polymerisation, through tuning of the acid/base nature [7], in contrast acidic supports, such as zeolites, enhance ethanol dehydration the formation of ethylene increase coking and deactivation [6]. Basic oxides of Ca and Mg have been used to increase H 2 production performance via sorptionenhance steam reforming [8,9], praseodymium and barium oxides have also promoted enhance steam reforming activity through reduced Ni sintering [10,11], whereas rare earth and transition metal oxides, e.g.…”