Tuning the selectivity for ring-opening reactions of methylcyclopentane over Pt catalysts: A mechanistic study from first-principles calculations

► DFT-based mechanistic study on ring-opening of methylcyclopentane over Pt surfaces. ► Modeling large particles by flat Pt(1 1 1), defect-rich particles by stepped Pt(2 1 1). ► Selectivity is controlled by the height of the C-C scission barrier. ► On Pt(1 1 1), branched methylpentanes favored products, n-hexane formation impeded. ► At step edges of Pt(2 1 1), barrier for ring-opening to form n-hexane reduced.