10.1021/acsomega.6b00462.s001 Ryan Lacdao Arevalo Ryan Lacdao Arevalo Susan Meñez Aspera Susan Meñez Aspera Mary Clare Sison Escaño Mary Clare Sison Escaño Hiroshi Nakanishi Hiroshi Nakanishi Hideaki Kasai Hideaki Kasai Ru-Catalyzed Steam Methane Reforming: Mechanistic Study from First Principles Calculations American Chemical Society 2017 activation Ru-Catalyzed Steam Methane Reforming First Principles Calculations Elucidating bond formation SMR CH catalyst O-containing species calculation surface conversion dissociative adsorption process 2017-04-05 08:19:01 Journal contribution https://acs.figshare.com/articles/journal_contribution/Ru-Catalyzed_Steam_Methane_Reforming_Mechanistic_Study_from_First_Principles_Calculations/4817998 Elucidating the reaction mechanism of steam methane reforming (SMR) is imperative for the rational design of catalysts for efficient hydrogen production. In this paper, we provide mechanistic insights into SMR on Ru surface using first principles calculations based on dispersion-corrected density functional theory. Methane activation (i.e., C–H bond cleavage) was found to proceed via a thermodynamically exothermic dissociative adsorption process, resulting in (CH<sub><i>y</i></sub> + <i>z</i>H)* species (“*” denotes a surface-bound state, and <i>y</i> + <i>z</i> = 4), with C* and CH* being the most stable adsorbates. The calculation of activation barriers suggests that the conversion of C* into O-containing species via C–O bond formation is kinetically slow, indicating that the surface reaction of carbon intermediates with oxygen is a possible rate-determining step. The results suggest the importance of subsequent elementary reactions following methane activation in determining the formation of stable carbon structures on the surface that deactivates the catalyst or the conversion of carbon into O-containing species.