AuCu Aerogels with Intriguing Surface Electronic Modulation as Highly Active and Stable Electrocatalysts for Oxygen Reduction and Borohydride Oxidation

We for the first time reported the successful synthesis of self-assembled AuCu aerogels via a one-pot kinetically-controlled approach. The startling electronic modulation effect of Cu on Au was observed across the entire alloy composition range, where the optimal upshift of d-band center for the highest activities was 0.24 eV. Due to the combination of nanoporous architecture and robust electronic effect, the Au52Cu48 aerogels exhibit more enhanced catalytic performance for oxygen reduction reaction (ORR) and direct borohydride oxidation reaction (BOR) compared to the commercial Pt/C catalysts. The specific and mass ORR activities on Au52Cu48 aerogels are 4.5 and 6.3 times higher than Pt/C, respectively, with negligible activity decay even after 10,000 cycles and 40,000 s duration. For BOR, the Au52Cu48 aerogels also exhibit far better selectivity and activity relative to Pt/C. The newly AuCu aerogels show great potentials as a promising alternative for Pt-based catalyst in fuel cells.