Subsurface Carbon-Induced Local Charge of Copper for On-Surface Displacement Reaction

TL;DR

This paper demonstrates that subsurface carbon doping in copper induces local charge changes that significantly enhance its catalytic activity for on-surface displacement reactions at room temperature.

Contribution

It reveals the atomic-scale mechanism by which subsurface carbon modifies copper's surface charge and catalyzes proton displacement reactions, a novel insight into copper carbide catalysis.

Findings

Subsurface carbon induces up to +0.30 e/atom charge on surface Cu.

Enhanced deprotonation rate due to reduced energy barrier.

Formation of a robust Cuδ+ surface for on-surface synthesis.

Abstract

Transition metal carbides have sparked unprecedented enthusiasm as high-performance catalysts in recent years. Still, the catalytic properties of copper (Cu) carbide remain unexplored. By introducing subsurface carbon (C) to Cu(111), displacement reaction of proton in carboxyl acid group with single Cu atom is demonstrated at the atomic scale and room temperature. Its occurrence is attributed to the C-doping induced local charge of surface Cu atoms (up to +0.30 e/atom), which accelerates the rate of on-surface deprotonation via reduction of the corresponding energy barrier, thus enabling the instant displacement of a proton with a Cu atom when the molecules land on the surface. Such well-defined and robust Cu$^{\delta +}$ surface based on the subsurface C doping offers a novel catalytic platform for on-surface synthesis.