ACS Applied Materials & Interfaces
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2024
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IF 8.3
Zheng Tang,Yongjia Li,Lanlan Shi,Kaixin Zhang,Yingjie Ji,Xiaoxuan Wang,Yebo Yao,Xia Liu,Dewei Wang,Kaiqi Nie,Jiangzhou Xie,Zhiyu Yang,Yi-Ming Yan
Direct formate fuel cells have gained traction due to their eco-friendly credentials and inherent safety. However, their potential is hampered by the kinetic challenges of the formate oxidation reaction (FOR) on Pd-based catalysts, chiefly due to the unfavorable adsorption of hydrogen species (Had). These species clog the active sites, hindering efficient catalysis. Here, we introduce a straightforward strategy to remedy this bottleneck by incorporating Pd with Cu to expedite the removal of Pd–Had in alkaline media. Notably, Cu plays a pivotal role in bolstering the concentration of hydroxyl adsorbates (OHad) on the surface of catalyst. These OHad species can react with Had, effectively unblocking the active sites for FOR. The as-synthesized catalyst of PdCu/C exhibits a superior FOR performance, boasting a remarkable mass activity of 3.62 A mg–1. Through CO-stripping voltammetry, we discern that the presence of Cu in Pd markedly speeds up the formation of adsorbed hydroxyl species (OHad) at diminished potentials. This, in turn, aids the oxidative removal of Pd–Had, leveraging a synergistic mechanism during FOR. Density functional theory computations further reveal intensified interactions between adsorbed oxygen species and intermediates, underscoring that the Cu–Pd interface exhibits greater oxyphilicity compared to pristine Pd. In this study, we present both experimental and theoretical corroborations, unequivocally highlighting that the integrated copper species markedly amplify the generation of OHad, ensuring efficient removal of Had. This work paves the way, shedding light on the strategic design of high-performing FOR catalysts.
研究领域:
催化
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电化学
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材料科学
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燃料电池
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理论化学
✓ 已验证
DOI
PubMed
高影响因子
Microbial Cell Factories
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2020
·Vol. 19
·期 1
·1-11
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IF 4.187
Xiong Liang-Bin,Liu Hao-Hao,Zhao Ming,Liu Yong-Jun,Song Lu,Xie Zhi-Yong,Xu Yi-Xin,Wang Feng-Qing,Wei Dong-Zhi
Background The bioconversion of phytosterols into high value-added steroidal intermediates, including the 9 α -hydroxy-4-androstene-3,17-dione (9-OHAD) and 22-hydroxy-23,24-bisnorchol-4-ene-3-one (4-HBC), is the cornerstone in steroid pharmaceutical industry. However, the low transportation efficiency of hydrophobic substrates into mycobacterial cells severely limits the transformation. In this study, a robust and stable modification of the cell wall in M. neoaurum strain strikingly enhanced the cell permeability for the high production of steroids. Results The deletion of the nonessential kasB , encoding a β-ketoacyl-acyl carrier protein synthase, led to a disturbed proportion of mycolic acids (MAs), which is one of the most important components in the cell wall of Mycobacterium neoaurum ATCC 25795. The determination of cell permeability displayed about two times improvement in the kasB -deficient strain than that of the wild type M. neoaurum . Thus, the deficiency of kasB in the 9-OHAD-producing strain resulted in a significant increase of 137.7% in the yield of 9 α -hydroxy-4-androstene-3,17-dione (9-OHAD). Ultimately, the 9-OHAD productivity in an industrial used resting cell system was reached 0.1135 g/L/h (10.9 g/L 9-OHAD from 20 g/L phytosterol) and the conversion time was shortened by 33%. In addition, a similar self-enhancement effect (34.5%) was realized in the 22-hydroxy-23,24-bisnorchol-4-ene-3-one (4-HBC) producing strain. Conclusions The modification of kasB resulted in a meaningful change in the cell wall mycolic acids. Deletion of the kasB gene remarkably improved the cell permeability, leading to a self-enhancement of the steroidal intermediate conversion. The results showed a high efficiency and feasibility of this construction strategy.
研究领域:
生物化学
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微生物学
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制药工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ACS Omega
·
2022
·
IF 4.132
Jialu Huang,Zhiming Ni,Xiaofan Song,Han Li,Xiaolei Chen,Aichuang Zhang,Hu Yang,Yuan Liu,Peng Zhu,Ping Hua,Xiaolei Yuan
PdPb nanocrystals have drawn considerable attention due to their excellent catalytic properties, while their practical applications have been impeded by the severe degradation of activity, which is caused by the adsorption of intermediates (especially CO) during the operation. Herein, we first present porous PdPb alloys with the incorporation of amorphous Pb(OH)2 species as highly active and stable electrocatalysts. Alloying Pd with Pb species is initially proposed to optimize the Pd–Pd interatomic distance and adjust the d-band center of Pd. Importantly, the amorphous Pb(OH)2 species are beneficial to promoting the formation of OHad and the removal of COad. Therefore, PdPb-Pb(OH)2 catalysts show a mass activity of 3.18 A mgPd–1 and keep excellent stability for the ethanol oxidation reaction (EOR). In addition, further CO stripping and a series of CO poisoning experiments indicate that PdPb-Pb(OH)2 composites possess much better CO tolerance benefiting from the tuned electronic structure of Pd and surface incorporation of Pb(OH)2 species.
研究领域:
材料科学
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电化学
·
催化
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）