ACS Applied Materials & Interfaces
·
2019
·
IF 8.456
Junfang Ding,Liping Li,Haorui Zheng,Ying Zuo,Xiyang Wang,Huixia Li,Shaoqing Chen,Dan Zhang,Xingliang Xu,Guangshe Li
Nanomaterials are widely used as redox-type reaction catalysts, while reactant adsorption and O2 activation are hardly to be promoted simultaneously, restricting their applications in many important catalytic fields such as preferential CO oxidation (CO-PROX) in H2-rich stream. In this work, an interface-enhanced Co3O4–CuCoO2 nanomesh was initially synthesized by a hydrothermal process using aluminum powder as a sacrificial agent. This nanomesh is systematically characterized by powder X-ray diffraction, scanning electron microscopy, transmission electron microscopy, N2 adsorption, X-ray photoelectron spectroscopy, UV–vis absorption spectroscopy, Raman spectroscopy, X-ray absorption near-edge spectroscopy, hydrogen temperature-programmed reduction, and oxygen temperature-programmed desorption. It is demonstrated that the nanomesh possesses high-density nanopores, enabling a large number of CO adsorption sites exposed to the surface. Meanwhile, electron transfer from O2– to Co3+/Co2+ and the weakened bonding strength of Co–O bond at surfaces promoted the oxygen activation and redox ability of Co3O4. When tested as a catalyst for CO-PROX, this nanomesh with an optimized pore structure and a surface electronic structure, exhibits a strikingly high catalytic oxidation activity at low temperatures as well as a broader operation temperature window (i.e., CO conversion >99.0%, 100–200 °C) in the CO selective oxidation reaction. The present finding should be highly useful in promoting the quest for better CO-PROX catalysts, a hot topic for proton exchange membrane fuel cells and automotive vehicles.
研究领域:
催化材料
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能源化学
·
燃料电池
✓ 已验证
产品关联
DOI
PubMed
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
·
2025
·
IF 9
Yeshuang Wang,Mingxian Duan,Zhelin Su,Chao Yang,Bingning Wang,Jiawei Kou,Huiling Fan
The abundant Fe 3+ Lewis acidic sites and well-developed pore structure endow the Fe-MOFs with great potential for H 2 S catalytic oxidation at room temperature, but their performance is inferior owing to the insufficient redox ability of the Fe 3+ species inherent in frameworks. Herein, an effective protocol was proposed for the first time to remarkably improve the catalytic oxidation performance of MIL-100(Fe) under ambient conditions through the introduction of Fe 2+ coordinatively unsaturated site (CUS) species into the framework. As expected, the sample after modification had a superior H 2 S breakthrough capacity of 267.3 mg S/g, an 18.4-fold increase compared with that without Fe 2+ CUS (14.5 mg S/g). The introduced Fe 2+ species triggered the Fe 3+ /Fe 2+ redox cycle for H 2 S catalytic oxidation by enhancing the oxidative ability of the Fe 3+ CUS intrinsic to the framework. Moreover, the Fe 2+ CUS was also found act as an active site for O 2 activation into O 2 ∙– , which not only provides an additional pathway for H 2 S catalytic oxidation but also accelerates the redox cycling of Fe 3+ /Fe 2+ during the catalytic oxidation process. On the basis of the experimental findings, a plausible catalytic mechanism involving mixed-valence iron sites in MIL-100(Fe) was proposed.
研究领域:
材料科学
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催化化学
✓ 已验证
产品关联
DOI
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
·
2023
·
IF 8.6
Fan Liu,Jing Ding,Qingliang Zhao,Guanshu Zhao,Kun Wang,Lili Li,Shuyan Guan
Advance oxidation process (AOP) is a promising way for micropollutants treatment, but the consumption of chemicals and energies limits its large-scale application. To address this issue, a novel boron-doped biochar (BBC) system was developed for the efficient removal of micropollutants, requiring no external energy or oxidant. Herein we demonstrated that the synthesized BBC could efficiently activate the dissolved oxygen (O 2 ) in the water or oxidize micropollutant directly. The complete sulfamethoxazole (SMX) could be removed within 30 min by the BBC synthesized at 600 °C (BBC-600). The experiments on material characterization and removal performance with quenchers revealed that the introduction of boron into biochar increased the active sites for O 2 activation, including persistent free radicals (PFRs) and boron moieties (BC 3 , BCO 2 , and BC 2 O) on the biochar. The generated reactive oxidation species (ROS), mainly O 2 − , were responsible for the SMX degradation in this BBC system. Different performance of aged experiments in air and N 2 conditions indicated that PFRs could also directly oxidize SMX. Density functional theory (DFT) was used to further illustrate the inner mechanism of enhanced electron transfer via boron moieties for O 2 activation and SMX degradation. Electrons of the adsorbed micropollutant could be transferred to boron moieties, and then trapped by O 2 in water to produce O 2 − and 1 O 2 for SMX degradation. This study provided a new insight into the structure–activity relationship of B-doped biochar for the direct and indirect degradation of micropollutant, and opened a new avenue for micropollutant degradation without external energy and oxidant.
研究领域:
环境科学
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材料科学
✓ 已验证
产品关联
DOI
高影响因子
Science Advances
·
2017
·Vol. 3
·期 6
·
IF 0
Pengwei Wang,Guofeng Zhao,Yu Wang,Yong Lu
Oxidative coupling of methane (OCM) is a promising method for the direct conversion of methane to ethene and ethane (C2 products). Among the catalysts reported previously, Mn2O3-Na2WO4/SiO2 showed the highest conversion and selectivity, but only at 800° to 900°C, which represents a substantial challenge for commercialization. We report a TiO2-doped Mn2O3-Na2WO4/SiO2 catalyst by using Ti-MWW zeolite as TiO2 dopant as well as SiO2 support, enabling OCM with 26% conversion and 76% C2-C3 selectivity at 720°C because of MnTiO3 formation. MnTiO3 triggers the low-temperature Mn2+↔Mn3+ cycle for O2 activation while working synergistically with Na2WO4 to selectively convert methane to C2-C3. We also prepared a practical Mn2O3-TiO2-Na2WO4/SiO2 catalyst in a ball mill. This catalyst can be transformed in situ into MnTiO3-Na2WO4/SiO2, yielding 22% conversion and 62% selectivity at 650°C. Our results will stimulate attempts to understand more fully the chemistry of MnTiO3-governed low-temperature activity, which might lead to commercial exploitation of a low-temperature OCM process.
研究领域:
化学工程
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催化
·
能源化学
✓ 已验证
产品关联
DOI
PubMed
ACS Catalysis
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2025
·
IF 13.1
Weina Yang,Yachao Wang,Yaxiong Wei,Guofeng Zhao,Weixin Huang,Cong Fu
Photocatalytic oxidative coupling of methane (OCM) offers a sustainable pathway for direct conversion of methane into value-added hydrocarbons, yet faces persistent challenges in balancing efficient methane activation with suppression of overoxidation. Here, we present a TiO2-based photocatalyst decorated with highly dispersed Ag–Co dual sites that achieves superior performance in continuous-flow OCM. The optimized AgCo–TiO2 system demonstrates a remarkable C2 hydrocarbon production rate of 1.7 mmol g–1 h–1 with 91% selectivity while maintaining stable operation for over 30 h. In situ spectroscopic analyses indicate that the introduced Co species induce mobile-charge imbalances, driving the directional transfer of photogenerated electrons and effectively suppressing electron–hole recombination. Coupled with Ag serving as a catalytic center, these effects synergistically enhance O2 activation, C–H bond cleavage, and selective C–C coupling, thereby contributing to the superior catalytic performance. This work provides valuable mechanistic insights into the photocatalytic OCM process, highlighting the pivotal role of precisely engineered charge transfer pathways in enabling efficient methane-to-C2 conversion.
研究领域:
光催化
·
材料科学
·
化学工程
·
环境化学
·
能量转换
✓ 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）