Autothermal Reforming of Bio-ethanol: A Short Review of Strategies Used to Synthesize Coke-Resistant Nickel-Based Catalysts

The paper presents a short review of strategies used to develop coke resistant, nickel-based, catalysts for autothermal reforming of ethanol to hydrogen. Autothermal reforming of ethanol can be used in conjunction with pronton-exchange membrane fuel cells (PEMFCs) in the transportation sector, stationary and portable applications to replace the use of fossil fuels. Nickel-based catalysts are used in commercial processes for their high carbon-carbon bond cleavage and low cost compared to noble metals. However, the use of nickel-based catalysts is challenged by rapid deactivation caused by coke formation. A considerable effort is expended on innovating strategies to develop coke resistant nickel-based catalysts. The strategies reviewed in this paper are (i) the use of catalysts' preparation methods targeting high dispersion of nickel nanoparticles smaller than the critical size of 10 nm (nm); (ii) modifying commonly used acidic supports (alumina, silica et cetera) to passivate the acidity to inhibit the production of coke precursor-ethylene; (iii) the addition of promoters and second active metals to promote supports and the active phase; (iv) controlling operating conditions to inhibit coke formation and the use of precursors with well-defined structures to stabilize highly dispersed nickel nanoparticles. [GRAPHICS] .