First-principles study of metal-biphenylene interfaces: structural, electronic, and catalytic properties

Abstract: We employ first-principles density functional theory (DFT) calculations to investigate the structural, electronic, and catalytic properties of biphenylene supported on various metal substrates. The substrates considered are the (111) surfaces of Ag, Au, Ni, Pd, Pt, Cu, Al, and the Cu$_3$Au alloy. Our results reveal how the interaction between biphenylene and the substrate governs its stability, degree of corrugation, electronic hybridization, and interfacial charge transfer. In particular, we observe a clear trend where weakly interacting metals preserve the intrinsic features of biphenylene, while more reactive substrates lead to significant structural and electronic modifications. We further evaluate the hydrogen evolution reaction (HER) activity of these systems, showing that certain metal supports, especially Pd, Pt, Ag, and Cu, can enhance the catalytic performance of biphenylene. Notably, Ag and Cu combine good catalytic activity with lower cost and chemical stability, offering a promising balance for practical applications. These findings provide insights into the design of biphenylene-metal interfaces, supporting their use in next-generation electronic and catalytic devices.