Unveiling the d‐Orbital Occupancy Driven Push‐Pull Effect on Pathway Selectivity in 1,2‐Dichloroethane Catalytic Combustion

ABSTRACT

Unraveling the link between electronic structure and reaction pathway is key to regulating 1,2‐DCE catalytic combustion and reducing toxic byproducts. In this work, we dope the full series of 3d transition metals (Sc to Zn) into SBA‐15‐supported LaMnO3 perovskite and show that dopant d‐orbital occupancy determines the reaction pathway via a directionally polarized push‐pull configuration. Low‐occupancy dopants (Sc, Ti, V, Cr) withdraw electrons from Mn, forming electron‐rich sites that donate electrons to adsorbed 1,2‐DCE, moderately activating the C─H bond and driving the dehydrochlorination pathway to produce VC. In contrast, high‐occupancy dopants (Fe, Co, Ni, Cu, Zn) push electrons toward Mn, generating electron‐deficient sites that strongly extract electrons from 1,2‐DCE, thereby promoting C─Cl bond cleavage and oxygen incorporation to yield ECH. Using S‐LMO‐V (T _90% = 199.7 °C) and S‐LMO‐Cu (T _90% = 224.8 °C) as representative catalysts, S‐LMO‐V exhibits higher activity, with a degradation pathway dominated by the less toxic VC, attributed to its moderate adsorption strength and the lower dechlorination barrier provided by electron‐rich V sites. Conversely, electron‐deficient Cu sites over‐stabilize the substrate and steer the reaction toward ECH. This work establishes the d‐orbital‐mediated push‐pull effect as a generalizable descriptor for pathway selectivity, guiding selective combustion of chlorinated VOCs and beyond.