INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
·
2017
·
IF 3.582
Haidong Chen,Feng Zhang,Xianwen Sun,Weifeng Zhang,Guoqiang Li
We systematically investigated the impact of reaction atmosphere on the Pt cocatalyst photodeposition and hydrogen evolution . A long induction period which is hardly found in close-system appears in the presence of oxygen, and is affected by the concentration of chloroplatinic acid. The Pt cocatalyst is metal state and contributes to the electronic states near Fermi level judging from the valence band X-ray photoelectron spectrum. The cocatalyst metal Pt will reduce the surface photovoltage signals due to the metal feature. The hydrogen evolution rate increased and reached a platform with increasing the Pt coverage on the surface of photocatalyst which is characterized by the Pt:Ti atomic ratio.
研究领域:
材料科学
·
催化化学
✓ 已验证
产品关联
DOI
高影响因子
Chemical Science
·
2025
·
IF 7.4
Jiye Feng,Danni Shi,Fei Wang,Yiming Zou,Weicheng Li,Wenbiao Zhang,Huai-Jun Lin,Yuying Meng,Qingsheng Gao
The electrochemical reconstruction of metal-organic frameworks (MOFs) offers a promising approach for in situ fabrication of high-performance electrocatalysts. However, this innovation is often hindered by unpredictable structural transformations due to the complex thermodynamic and kinetic interplay of such multiple electrochemical and chemical processes. Herein, the reaction-atmosphere (Ar or CO2) guided reconstruction of Cu-based MOFs to Cu nanoparticles with mix-valence surface/interfaces was for the first time investigated to unravel the kinetic contribution made by intermediate chemisorption. As shown, Cu-1,3,5-benzenetricarboxylate (HKUST-1) with frangible Cu-O4 nodes undergoes thermodynamically favored reduction quickly upon applying cathodic potentials, followed by the varied surface changes kinetically governed by the intermediates of hydrogen evolution or CO2 reduction reactions (HER or CO2RR). Under an Ar atmosphere, the predominant HER increases the [OH-] of the microenvironment near cathodes and thereby boosts the re-oxidation of in-situ formed Cu toward Cu/Cu2O interfaces. Conversely, the CO2RR facilitates the strong adsorption of *CO on Cu surfaces, effectively preserving Cu(0) species. Thanks to the rich Cu/Cu2O interfaces with the lowered energy barrier for *CO-*CO coupling during the subsequent CO2RR test, the restructured electrocatalysts under Ar affords the obviously improved CO2-to-C2H4 conversion as compared with the counterpart restructured under CO2. Such atmosphere-controlled reconstruction strategy is further validated using CuBDC (BDC = 1,4-benzenedicarboxylate) with labile Cu-O4 nodes, while CuPz2 (Pz = pyrazole) with robust Cu-N4 coordination remains stable, highlighting the framework-dependent nature. These findings establish atmosphere-controlled reconstruction of metastable MOFs as a powerful tool for rational electrocatalyst design.
研究领域:
材料科学
·
电催化
·
能源化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Science Advances
·
2023
·Vol. 9
·期 24
·
IF 13.6
Mingrui Wang,Peng Wang,Guanghui Zhang,Zening Cheng,Mengmeng Zhang,Yulong Liu,Rongtan Li,Jie Zhu,Jianyang Wang,Kai Bian,Yi Liu,Fanshu Ding,Thomas P. Senftle,Xiaowa Nie,Qiang Fu,Chunshan Song,Xinwen Guo
The decomposition of cobalt carbide (Co 2 C) to metallic cobalt in CO 2 hydrogenation results in a notable drop in the selectivity of valued C 2+ products, and the stabilization of Co 2 C remains a grand challenge. Here, we report an in situ synthesized K-Co 2 C catalyst, and the selectivity of C 2+ hydrocarbons in CO 2 hydrogenation achieves 67.3% at 300°C, 3.0 MPa. Experimental and theoretical results elucidate that CoO transforms to Co 2 C in the reaction, while the stabilization of Co 2 C is dependent on the reaction atmosphere and the K promoter. During the carburization, the K promoter and H 2 O jointly assist in the formation of surface C * species via the carboxylate intermediate, while the adsorption of C * on CoO is enhanced by the K promoter. The lifetime of the K-Co 2 C is further prolonged from 35 hours to over 200 hours by co-feeding H 2 O. This work provides a fundamental understanding toward the role of H 2 O in Co 2 C chemistry, as well as the potential of extending its application in other reactions.
研究领域:
催化化学
·
化学工程
·
材料科学
·
可持续能源
·
多相催化
✓ 已验证
DOI
高影响因子
FUEL
·
2025
·
IF 7.5
Lipeng Guo,Jihui Yao,Haibo Zhu
Methylcyclohexane (MCH) dehydrogenation for H 2 production is a promising route in liquid organic hydrogen carriers technology. However, there are few reports on the influence of Pt size on methylcyclohexane dehydrogenation under different reaction atmospheres. In this study, a series of Pt/Al 2 O 3 catalysts with Pt particle sizes ranging from 0.67 to 1.26 nm were prepared via the impregnation method. The influences of Pt particle size on MCH dehydrogenation under H 2 and N 2 atmospheres were investigated. The toluene (TOL) product adsorbed on Pt site has a significant effect on the activity and stability of Pt/Al 2 O 3 for MCH dehydrogenation. Under N 2 atmosphere, the poisoning of Pt/Al 2 O 3 by toluene leads to a low activity in this reaction. By contrast, under H 2 atmosphere, the adsorption of toluene can be effectively inhibited by H 2 , and thus an enhanced catalytic performance can be achieved. The catalyst with Pt size of 0.67 nm exhibits a high turnover frequency (TOF) of 33,530 mol H2 ·mol Pt −1 ·h −1 , corresponding to a H 2 evolution rate of 2,865 mmol·g Pt −1 ·min −1 . These findings provide a deeper understanding of the dependence of catalyst structure and reaction conditions on MCH dehydrogenation, offering fundamental guidance for the design of efficient catalysis system for MCH dehydrogenation.
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）