Elucidating the Mechanism of Simultaneous Activation of CH₄ and CO₂ Mediated by Single Group 10 Metal Anions in Gas Phase

Abstract

Quantum chemistry calculations predict that besides the reported single metal anion Pt À , Ni À can also mediate the coconversion of CO 2 and CH 4 to form [CH 3 À M(CO 2 )À H]complex, followed by transformation to CÀ C coupling product [H 3 CCOOÀ MÀ H] À (A), hydrogenation products [H 3 CÀ MÀ OCOH] À (B) and [H 3 CÀ MÀ COOH] À . For Pd À , a fourth product channel leading to PdCO 2 À …CH 4 becomes more competitive. For Ni À , the feed order must be CO 2 first, as the weaker donor-acceptor interaction between Ni À and CH 4 increases the CÀ H activation barrier, which is reduced by [NiÀ CO 2 ] À . For Ni À /Pt À , the highly exothermic products A and B are similarly stable with submerged barrier that favors B. The smaller barrier difference between A and B for Ni À suggests the CÀ C coupling product is more competitive in the presence of Ni À than Pt À . The charge redistribution from M À is the driving force for product B channel. This study adds our understanding of single atomic anions to activate CH 4 and CO 2 simultaneously.

Graphene-Supported Single-Atom Ni as High-Performance Catalyst for Direct Methane-to-Methanol Conversion

“…The above conclusion is consistent with previous gas-phase studies of MO + catalyzing CH 4 to CH 3 OH that M = Ni affords the best reactivity and selectivity among M = Ni, Pd, and Pt. − This inspiring agreement indicates that gas-phase studies on simple molecules/ions are powerful to predict the catalytic behavior of heterogeneous catalysts that bear the same functional units. − …”