||In recent years, in order to reduce the use of petroleum resources, the development of alternative energy sources has become an important goal. Alternative energy sources such as solar energy, wind power, hydrogen energy, geothermal, and biomass energy have been developed. Fuel cells are an important element of alternative energy due to their high efficiency and low pollution, with hydrogen the best material due to the convenience in obtaining it from biomass energy and petrochemical materials. In general, hydrogen is produced from ethanol decomposition, steam reforming, and partial oxidation, as well as oxidative steam reforming (OSR) and other reactions. The most important issues for production are how to prevent poisoning from these reactions. Due to its specific advantages, the OSR reaction is studied here to improve efficiency by investigating its mechanism at the nanometer scale.|
In this work, the reaction mechanism of the OSR of ethanol on the Rh(111) surface was systematically examined by density functional theory (DFT) and the kinetic Monte Carlo (kMC) method calculation was carried out to simulate the experimental condition on an Rh-based catalyst. First, DFT was employed to optimize the local minimums and transition states for a series of elementary steps. Next, the statistical mechanics of OSR were simulated by kMC, and adsorption, desorption, and combination of the chemical reactions were illustrated under steady state conditions. According to the experimental results, various fractions of oxygen/ethanol (0.687/1, 0.802/1, 0.916/1, 1.030/1, 1.145/1, 1.260/1, 1.374/1, 1.489/1, and 1.603/1) and water/ethanol (1/1, 3/1, 5/1, 10/1,) were adjusted to investigate the effects of oxygen and water in the OSR of ethanol reaction. The computed kMC results show that the pathways will be affected by increasing oxygen and water content and adjustments can decrease CO and enhance CO2 production. This computational study can further help to predict the optimal operational conditions of OSR in order to produce the best performance.