Complete oxidation of ethanol is a pressing need for direct ethanol fuel cells (DEFCs) owning to high energy conversion. However, it holds great challenges on account of sluggish kinetics for C C bond cleavage and high susceptibility to CO poisoning. Herein, ternary PtPdCu nanocrsytals are synthesized and investigated for complete oxidation of ethanol. The obtained ternary PtPdCu nanodendrites (PtPdCu NDs) have a stepped surface, providing abundant active sites. Due to the structural and synergistic effects, ternary PtPdCu NDs exhibit a mass activity of 5.59 A mg PtPd −1 and specific activity of 15.82 mA cm −2 towards ethanol oxidation reaction, which are 6.4 and 3.6 times larger than that of commercial Pt/C. Further studies reveal that ternary PtPdCu NDs show strong abilities of CO anti-poisoning and C C bond cleavage, enhancing the C 1 pathway selectivity.
Designing multifunctional catalysts for low-temperature co-oxidation of volatile organic compounds (VOCs) and CO is challenging, as conventional catalysts cannot simultaneously achieve VOCs activation and CO poisoning resistance below 200 °C—where CO preferentially adsorbs and severely inhibits VOCs oxidation. Herein, we proposed a density functional theory (DFT)-guided atomic engineering strategy integrating d-band center modulation and adsorption energy screening to construct metal-organic frameworks (MOFs)-hosted Au-Pt single-atom alloys (SAAs). By leveraging the coordination confinement of UiO-66 to stabilize Au-Pt SAAs sites, the optimized Au-Pt SAAs/UiO-66 catalyst achieved exceptional performance in co-oxidation of toluene and CO, attaining 90 % toluene conversion at 160 °C with robust stability under CO-poisoning conditions. Mechanistic studies and DFT calculations revealed that atomically dispersed Au sites induced Pt δ− -Au δ+ charge polarization on Pt nanoparticles charge polarization via interfacial electron transfer, weakening CO adsorption while enhancing toluene activation through dual-pathway mechanisms (Eley-Rideal and Langmuir-Hinshelwood) mechanisms. This synergy decouples the traditional trade-offs between activity and stability, offering a 4.7-fold higher turnover frequency than conventional Pt catalysts. Our work established a paradigm for electronic cooperativity in MOF-hosted SAAs, providing atomic-level insights into the design of multifunctional catalysts for environmental remediation.
Jianpo Chen,Xiaohong Tan,Weidong He,Yingying Guo,Yuhang Xiao,Hao Cui,Chengxin Wang
Efficient ethanol oxidation reaction (EOR) catalysts with anti-poisoning ability and high selectivity are in high demand for the widespread application of direct ethanol fuel cells (DEFCs). Here, the PdSnW ternary alloy nanoparticles are synthesized by a facile solvothermal method and exhibit an enhanced EOR catalytic performance. CO stripping experiment, X-ray photoelectron spectroscopy and in situ Fourier transform infrared are employed to study the correlation between catalyst structure and EOR catalytic performance. The oxyphilic Sn and W not only provide dangling O-H bond, accelerating the subsequent oxidation of adsorbed intermediate CO species, but also moderate the electron state of Pd, enhancing the adsorption of CH3CH2OH, thus resulting in the promotion of C-C bond cleavage and an increased C1 selectivity. As a consequence, PdSnW alloy nanoparticle catalyst exhibit a better stability and a higher mass activity than those of Pd/C, PdSn and PdW, respectively. This work not only offers novel insights to strategically design highly efficient electrocatalysts for ethanol oxidation, but also further clarifies the inherent structure-activity relationship.
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