Zou, J.Iqbal, M.Vijayakumar, A.Wang, C.Macfarlane, D.R.Yamauchi, Y.Lee, C.-Y.Wallace, G.G.2025-07-212025-07-212020Journal of Materials Chemistry A, 2020; 8(16):8041-80482050-74882050-7496https://hdl.handle.net/2440/146153The understanding of the influence of hierarchically nanostructured architectures as support materials for catalysts loading, is critical towards development of efficient electrocatalytic interfaces. The knowledge on mass transport limitation of reactants within such catalyst-support structures remains elusive. Herein, we performed systematic investigation through a novel hierarchical 1D–3D structure by loading mesoporous Pd with an average pore size of ∼10 nm and wall thickness of ∼4 nm onto highly ordered TiO₂ nanotube arrays via pulse electrodeposition. Electrochemical CO₂ reductions achieved a CO₂-toformate faradaic conversion efficiency of 88 ± 2% under optimal conditions. Importantly, the product selectivity is found to depend significantly on the tube length, highlighting the influence of mass transport limitations of CO₂. This work offers vital insight into practical consideration in designing efficient catalyst-support interfaces with an optimal hierarchically geometry, that must optimise mass transport as well as electrochemical kinetics.en© The Royal Society of Chemistry 2020nanostructured architectures; Hierachy; Transport; catalyst-support structures; systematic investigation; novel hierarchical 1D–3D structure; TiO2; nanotube arrays; pulse electrodeposition; Electrochemical CO2Journal article10.1039/d0ta02077j2024-10-22626674