Singha Tukai, Tomar Shalini, Chakraborty Sudip, Das Shuvankar, Satpati Biswarup
Surface Physics & Material Science Division, Saha Institute of Nuclear Physics, A CI of Homi Bhabha National Institute, 1/AF Bidhannagar, Kolkata, 700064, India.
Material Theory for Energy Scavenging (MATES) Lab, Harish-Chandra Research Institute (HRI), A CI of Homi Bhabha National Institute, Chhatnag Road, Jhunsi, Prayagraj, 211019, India.
Small. 2024 Aug;20(32):e2309736. doi: 10.1002/smll.202309736. Epub 2024 Mar 8.
The direct alcohol fuel cells (DAFCs) rely on alcohol oxidation reactions (AORs) to produce electricity, which require catalysts with optimized electronic structure to accelerate the sluggish AORs. Herein, an epitaxial growth of Pd layer onto the pentatwinned Au@Ag core-shell nanorods (NRs) is reported to synthesize highly strained Au@AgPd core-shell NRs. The tensile strain in the AgPd shell of the Au@AgPd nanorods (NRs) arises not only from the core-shell lattice mismatch but also from twinning and lattice distortion occurring at the five twinned boundaries present in the structure. Theoretical simulations prove that the presence of tensile strains in the AgPd layer leads to a significant upward shift of the d-band center of the Pd site toward the Fermi level which remarkably changes the adsorption energy of alcohols on the surface. Highly strained Au@AgPd NRs show exceptional mass activities in electrochemical oxidation of biomass-derived alcohols (ethylene glycol, ethanol, and glycerol) reaching up to 18.66, 15.6, and 7.90 A mg , respectively. These values are 23.3, 23.6, and 23.2 times higher than commercial Pd/C catalysts. This strain engineering strategy set the platform for the design and synthesis of highly efficient and versatile catalysts for the construction of high-performance DAFCs.
直接醇类燃料电池（DAFCs）依靠醇氧化反应（AORs）发电，这需要具有优化电子结构的催化剂来加速缓慢的AORs。在此，报道了在五重孪晶Au@Ag核壳纳米棒（NRs）上外延生长Pd层以合成高应变Au@AgPd核壳纳米棒。Au@AgPd纳米棒（NRs）的AgPd壳层中的拉伸应变不仅源于核壳晶格失配，还源于结构中存在的五个孪晶界处发生的孪晶和晶格畸变。理论模拟证明，AgPd层中拉伸应变的存在导致Pd位点的d带中心显著向上移动至费米能级，这显著改变了醇在表面的吸附能。高应变Au@AgPd纳米棒在生物质衍生醇（乙二醇、乙醇和甘油）的电化学氧化中表现出优异的质量活性，分别高达18.66、15.6和7.90 A mg⁻¹。这些值分别比商业Pd/C催化剂高23.3、23.6和23.2倍。这种应变工程策略为设计和合成用于构建高性能DAFCs的高效通用催化剂奠定了基础。
