Complete Reaction Cycle for Methane-to-Methanol Conversion over Cu-SSZ-13: First-Principles Calculations and Microkinetic Modeling

The steadily increasing consumption of natural gas imposes a need to facilitate the handling and distribution fuel, which presently is compressed or condensed. Alternatively, reduced volatility increased tractability are achieved by converting chemical energy main component, methane, into liquid methanol. Previous studies have explored direct methane-to-methanol conversion, but suitable catalysts not yet been identified. Here, complete reaction cycle for conversion over Cu-SSZ-13 system studied using density functional theory. first step in migration Cu species along zeolite framework forming pair, necessary adsorption O2. Methane occurs CuOOCu CuOCu sites, consecutively, after returned its initial structure with two separate ions. A theory-based kinetic model shows high activity when water included mechanism, example, even at very low partial pressures water, results turnover frequency ∼1 450 K. apparent activation from (∼1.1 eV) close recent measurements. However, experimental always observe small amounts methanol compared formation more energetically preferred products, CO2. This selectivity described current mechanism as it does consider other species; however, suggest that selectivity, rather than inherent limitations, an important target improving yields humid systems. Moreover, closed oxidation methane has long sought, achieving this Cu-SSZ-13, study contributes one toward identifying catalyst conversion.