Formic acid (FA), as a safe and renewable hydrogen storage material, attracts extensive attention. Herein, an efficient catalyst Au 0.35 Pd 0.5 Ir 0.15 nanoalloy supported on NH 2 -N-rGO has been successfully synthesized and applied for hydrogen generation from FA. It is found by density function theory (DFT) calculation that addition of Ir into AuPd alloy can change the initial adsorption configuration of HCOOH* and thus reduce the energy barrier of rate determining step (RDS) of FA dehydrogenation . As a result, Au 0.35 Pd 0.5 Ir 0.15 /NH 2 -N-rGO displays 100% conversion, 100% selectivity even after 150 days for FA dehydrogenation at 298 K, and the initial turnover frequency (TOF) can reach the recorded value (12781.2 h −1 ) without any additives. More interestingly, it is proved to be a universal method to design the effective catalysts for hydrogen generation from FA by the high activities of other tri-metallic alloys with addition of other high γ elements (such as Pt, Rh, and Ru).
Developing precious-metal-free bifunctional oxygen reduction and evolution reaction (ORR/OER) electrocatalysts is of great significance for several key energy conversion and storage systems, yet remains a formidable challenge. Herein, we systematically designed Fe–Co–Ni trimetallic nanoalloys encapsulated in nitrogen-doped carbon nanotube@nanosheet frameworks (FeCoNi-NC) for application as effective bifunctional ORR/OER electrocatalysts. The rational structural design of FeCoNi-NC provides hierarchical porosity coupled with greatly increased effective electrochemical specific area for exposing abundant active sites and enhanced mass-transfer capability toward the ORR/OER. Experimental observations and theoretical calculations confirmed that Fe–Co–Ni nanoalloys interacting with pyridinic nitrogen-rich carbon synergistically optimized the adsorption/desorption free energies of oxygen intermediates, thus significantly enhancing the intrinsic ORR/OER activity. Consequently, FeCoNi-NC exhibits remarkable bifunctionality for the ORR (half-wave potential of 0.89 V) and OER (1.54 V at 10 mA cm−2) with ΔE = 0.65 V, and even outperforms Pt/C–RuO2 benchmarks. Moreover, the corresponding zinc–air battery shows large power density (315.2 mW cm−2), high capacity (803.78 mA h g−1 at 100 mA cm−2) and excellent cycling durability (over 100 hours at 50 mA cm−2), further testifying its practical applications. This work demonstrates an effective pathway to highly active non-precious-metal bifunctional catalysts toward sustainable energy technologies.
Yangping Zhang,Fei Gao,Caiqin Wang,Yukihide Shiraishi,Yukou Du
Engineering robust electrocatalysts is always a key point in direct alcohol fuel cells. Catalysts with a one-dimension (1D) structure are well studied and considered as promising candidates among various catalysts in the past decades; however, the precise regulation on the surface structure of 1D nanomaterials is still a worthy subject. By creatively introducing a trimetallic nanoalloy, core@multishell structure, and 1D nanowire (NW) morphology, we have constructed a kind of novel spiny PtFePd@PtFe/Pt core@multishell 1D NW catalysts with PtFePd as the core and PtFe/Pt as the multishell on the basis of improving catalytic property. The composition-optimized Pt5FePd2 1D NWs display remarkable catalytic properties for ethanol oxidation reaction and methanol oxidation reaction, in which mass activities are 4.965 and 4.038 A mg–1, 4.6 and 5.0 and 4.0 and 9.2-fold higher than Pt/C and Pd/C catalysts. Furthermore, the obtained Pt5FePd2 NWs can also retain favorable stability after durability tests. The unique core@multishell structure, spiny 1D NWs with many steps and kinks, and interior electronic and synergistic effect all contribute to the advanced catalytic performance. The present work has rationally designed the novel 1D PtFePd@PtFe/Pt core@multishell NW catalysts and offered a meaningful guideline for the designing of high-performance electrocatalysts.
危险品化学品经营许可证（带存储）