A reformer, which can also be referred to as a fuel processor, can convert a hydrocarbon fuel (e.g., methane, propane, natural gas, gasoline, diesel, gas oils, oxygenated hydrocarbons, and the like) to hydrogen or to a less complex hydrocarbon. More particularly, fuel reforming can comprise mixing a hydrocarbon fuel with air, water, and/or steam in a mixing zone of the reformer prior to entering a reforming zone of the reformer, and converting the hydrocarbon fuel into, for example, hydrogen (H2), byproducts (e.g., carbon monoxide (CO), methane (CH4), inert materials (e.g., nitrogen (N2), carbon dioxide (CO2), and water (H2O)). Common approaches can include steam reforming, partial oxidation, and dry reforming.
Steam reforming involves the use of a fuel and steam (H2O) that can be reacted in heated tubes filled with a catalyst(s) to convert the hydrocarbons into principally synthesis gas (hydrogen and carbon monoxide). The steam reforming reactions are endothermic, thus the steam reformers can be designed to transfer heat into the catalytic process. An example of the steam reforming reaction is as follows:CH4+H2O→CO+3H2 
Partial oxidation reformers are based on substoichiometric combustion to achieve the temperatures sufficient to reform the hydrocarbon fuel. Decomposition of the fuel to primarily hydrogen and carbon monoxide can occur through thermal reactions at high temperatures, e.g., about 700 degrees Celsius (° C.) to about 1,200° C. Catalysts have been used with partial oxidation systems (catalytic partial oxidation) to promote conversion of various fuels into synthesis gas. The use of a catalyst can result in acceleration of the reforming reactions and can provide this effect at lower reaction temperatures than those that would otherwise be required in the absence of a catalyst. An example of the partial oxidation reforming reaction is as follows:CH4+½O2→CO+2H2 
Dry reforming involves the creation of hydrogen and carbon monoxide in the absence of water, for example, using carbon dioxide as the oxidant. Dry reforming reactions, like steam reforming reactions, are endothermic processes. An example of the dry reforming reaction is depicted in the following reaction:CH4+CO2→2CO+2H2 
Practical reformers can comprise a combination of these idealized processes. Thus, a combination of air, water or recycled exhaust gas can be used as the oxidant in the fuel reforming process.
The catalyst material of the reformer can be disposed on a substrate (e.g., a ceramic material, a metal, and the like). It is noted that the substrate can be subjected to an extreme hydrothermal hydrogen reforming environment (e.g., greater than or equal to about 20 vol. % hydrogen at temperatures up to about 1600° C.), which can cause grain growth in the substrate that can lead to reformer degradation (e.g., cracking in the substrate, and the like).
Therefore, what is needed in the art is an improved reformer substrate.