Abstract
Bicontinuous nanoporous gold (NPG) is a high-performance catalyst characterized by its excellent electrochemical stability and immense active surface area with high electrolyte accessibility. However, the intrinsic catalytic activity of NPG is still lower compared to other metals (such as Pt), thus impeding its applicability in a commercial catalytic system. Herein, we incorporate secondary Pt metal with inherently strong catalytic activities into a zero-dimensional (0D) nanoporous gold bowl (NPGB) to develop Pt-NPGB bimetallic catalyst. Our strategy effectively exploits the highly accessible surface area of NPGB and the manipulative d-band electronic structure brought about by the synergistic intermetallic interaction for enhanced catalytic performance and durability. Deposition of Pt on the NPGB catalyst directly modulates its d-band electronic structure, with the electronic energy of Pt-NPGBs tunable between -3.93 to -4.24, approximating that of chemically resistant gold (-4.35 eV). This is vital to weaken the binding strength between Pt active sites and intermediate poisoning species. Together with the high Pt electrochemical active surface area (ECSA) of 17.1 mA/mu g(Pt) facilitated by NPGB cocatalyst, such synergistic effect enables the superior performance of Pt-NPGB hybrids over commercial Pt/C in methanol oxidation reaction (MOR), where an 11-fold and 227-fold better catalytic activity and durability are demonstrated even after an extended duration of 3600 s. Our study is therefore the first demonstration of NPGB on the exploitation of precisely modulated synergistic effect at the electronic level to control and boost catalytic performance. Furthermore, the chemically inert NPGB possesses an intrinsically higher gold surface area and electrolyte accessibility unique to 0D nanoparticle, hence empowering it as an immensely attractive cocatalytic platform extendable to a wide range of secondary metals. This is important to promote the catalytic performance for diverse electrochemical applications, especially in the field of energy, synthetic chemistry, and also environmental toxin degradation.