ADVANCED FUNCTIONAL MATERIALS
·
2023
·Vol. 33
·期 16
·2214215
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IF 19
Xiaosong Hu,Xinyu Liu,Xin Hu,Chaoyue Zhao,Qingxin Guan,Wei Li
Reverse water-gas shift (RWGS) reaction is the initial and necessary step of CO 2 hydrogenation to high value-added products, and regulating the selectivity of CO is still a fundamental challenge. In the present study, an efficient catalyst (CuZnN x @C-N) composed by Zn single atoms and Cu clusters stabilized by nitrogen sites is reported. It contains saturated four-coordinate Zn-N 4 sites and low valence CuN x clusters. Monodisperse Zn induces the aggregation of pyridinic N to form Zn-N 4 and N 4 structures, which show strong Lewis basicity and has strong adsorption for *CO 2 and *COOH intermediates, but weak adsorption for *CO, thus greatly improves the CO 2 conversion and CO selectivity. The catalyst calcined at 700 °C exhibits the highest CO 2 conversion of 43.6% under atmospheric pressure, which is 18.33 times of Cu-ZnO and close to the thermodynamic equilibrium conversion rate (49.9%) of CO 2 . In the catalytic process, CuN x not only adsorbs and activates H 2 , but also cooperates with the adjacent Zn-N 4 and N 4 structures to jointly activate CO 2 molecules and further promotes the hydrogenation of CO 2 . This synergistic mechanism will provide new insights for developing efficient hydrogenation catalysts.
研究领域:
化学
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催化材料科学
✓ 已验证
产品关联
DOI
高影响因子
FUEL
·
2024
·
IF 6.7
Bin Fu,Yuqiong Zhao,Shipeng Zhang,Ying Wang,Jun Liu,Guojie Zhang
Nickel-based catalysts frequently encounter significant challenges in achieving both high CO 2 conversion and superior CO selectivity during reverse water gas shift (RWGS) reactions. To address this issue, we developed a facile strategy to prepare highly dispersed Ni/CeO 2 catalysts by forming Ce 1−x Ni x O 2−y solid solutions. Under conditions of 300–600 °C, 0.1 MPa, and a gas hourly space velocity (GHSV) of 40,000 mL g cat −1 h −1 , the 5Ni/CeO 2 -A catalyst exhibited outstanding selectivity, approaching 100 %. The RWGS reaction rate reached 1332 μmol CO g Ni −1 s −1 and maintained stable for 50 h almost without deactivation. The formation of Ce 1−x Ni x O 2−y solid solution uniformly disperses numerous Ni species in the CeO 2 lattice, effectively inhibiting Ni aggregation. This highly dispersed Ni weakens CO adsorption and facilitates its direct desorption without excessive hydrogenation. Moreover, the catalyst remains well-dispersed state even after reduction. The formed Ce 1−x Ni x O 2−y solid solution generates abundant oxygen vacancies on the catalyst surface, enhancing H 2 dissociation. The catalyst’s pore size distribution is also modified, creating stacked pores that favor reactant diffusion and expose more active centers. In-situ DRIFTS experiments demonstrate that Ce-OH plays a pivotal role in CO 2 adsorption on the 5Ni/CeO 2 -A catalyst, while the stabilization of bicarbonate and formate intermediates by the highly dispersed Ni further promotes catalytic performance. This study introduces a novel preparation method and provides valuable insights for designing Ni-based catalysts with exceptional CO selectivity.
研究领域:
催化化学
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材料科学
✓ 已验证
DOI
高影响因子
Sustainable Energy & Fuels
·
2020
·Vol. 4
·期 6
·2937-2949
·
IF 5.503
Xin Hu,Xiaosong Hu,Qingxin Guan,Wei Li
Converting CO2 to CO via the reverse water gas shift (RWGS) reaction is an important route to reducing greenhouse gas emissions, and catalysts using copper and zinc as active components have been extensively studied for this reaction. Herein, the coordination and acid etching of trimesic acid (H3BTC) were used to assemble and regulate the Cu and ZnO components in the catalyst. First, Cu-HKUST-1 was synthesized by the self-assembly of H3BTC and copper ions, which limited the sintering and agglomeration of Cu nanoparticles in the subsequent carbonization and self-reduction process. Second, ZnO particles were etched by H3BTC to form the complex of H3BTC with Zn and to redisperse Zn species. Under the dual action of H3BTC, carbon-coated bimetal nanoparticles with a size of 2–6 nm were obtained on the fumed silica after pyrolysis at high temperature. The prepared Cu@C–ZnO/SiO2 catalyst can achieve 31.4% CO2 conversion and 99% CO selectivity in RWGS reaction in a fixed bed reactor at 400 °C and 3 MPa. Besides, we also found that the molar ratio of Cu/Zn, metal components, and the introduction order of H3BTC all affected the structure and composition of the catalyst, thus affecting the catalytic activity. This study provides an excellent strategy for the design and synthesis of catalysts containing copper and zinc components.
研究领域:
催化化学
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材料科学
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环境科学
✓ 已验证
产品关联
DOI
高影响因子
Journal of CO2 Utilization
·
2021
·
IF 7.132
Bowen Lu,Yongqing Xu,Zewu Zhang,Fan Wu,Xiaoshan Li,Cong Luo,Liqi Zhang
Cu-based catalysts had been widely used in CO 2 hydrogenation process for their excellent performance and high selectivity. Micron-sized Cu powder obtained by ball milling exhibited poor CO 2 activity for its large particle size and small specific surface area, limited its catalytic application. In this work, micron Cu powder was modified with CeO 2 species synthesized from different cerium precursor salts via a solution auto-combustion method to investigate CO 2 hydrogenation activity. This work revealed that CeO 2 species formed from cerium acetate precursor salt achieved excellent CO 2 performance (1.64 mol/g cat .h at 400 °C), which was 3.8 times and 6000 times higher than that from cerium nitrate salt or cerium chloride salt, respectively. Interestingly, a thick dense CeO 2 shell would be formed on micron Cu generated from cerium(III) chloride precursor salt, which inhibited CuO x reduction and had the opposite effect for RWGS reaction. In addition, the CuO x species in CeO 2 @Cu synthesized from cerium chloride salt resulted in the CH 4 selectivity. The enhancement performance of the CeO 2 @Cu prepared from cerium acetate salt and cerium nitrate salt could be attributed to the oxygen defects formed around the Cu-Ox-Ce interface area and metallic Cu in the RWGS reaction. Cerium precursor salts enhanced the structural integrity of CeO 2 @Cu and played a vital role in RWGS reaction. These results will support a new direction for exploring micron Cu powder in Cu-based catalysts for CO 2 utilization.
研究领域:
化学工程
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材料科学
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催化反应
✓ 已验证
产品关联
DOI
高影响因子
ACS Catalysis
·
2025
·
IF 13.1
Shiyan Li,Xu Liu,Jun Ma,Feifei Xu,Yuan Lyu,Siglinda Perathoner,Gabriele Centi,Yuefeng Liu
The high-temperature reverse water–gas shift (RWGS) is an industrially relevant reaction. Cu-based catalysts easily sinter and deactivate under these conditions. We demonstrate that it is possible to obtain high-performance and stable catalysts by modifying the mechanism of action. Cu/CeOx-MgO (denoted as Cu/CexMgy) catalysts were developed in which Cu nanoparticles mostly generate spillover H that migrates to support sites where CO2 is selectively reduced, with the rate controlled by the oxide–oxide CeOx-MgO interface. An optimal Cu/Ce0.05Mg0.95 catalyst (in terms of performance at the lowest possible Ce amount) exhibits a near-equilibrium CO2 conversion with a reaction rate of 516.0 μmol·gcat–1·s–1, near-total selectivity to CO at 600 °C, and a high space-velocity of 300,000 mL·gcat–1·h–1. These are among the top performances in the RWGS reaction. Extensive characterization data have proven that the surface-abundant Ce-[Ov]-Mg sites play a critical role in CO2 adsorption/activation as well as the carrier for the spillover of hydrogen species. The mechanism is substantially different from those indicated for Cu-based catalysts for CO2 hydrogenation. By decoupling H and CO2 activation sites and realizing efficient surface mobility of H-spillover species via an enhanced oxide–oxide interface, it is possible to maintain the overall stability and activity of the catalyst when the Cu nanoparticles sinter at a high temperature (i.e., ≥600 °C).
研究领域:
化学工程
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催化材料
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2023
·
IF 15.1
Zequn Zhang,Yuan Shu,Qian Liu,Shuxian Bi,Pengfei Zhang
Colloidal nanoparticles with uniform particle size distribution, tailored exposed facets, and controllable compositions appealed to broad interests in heterogeneous catalysis. Nevertheless, due to the strong attachment of capping agents to the nanoparticles, cleaning the nanoparticle surface without changing the size of nanoparticles remains a significant challenge. Herein, based on the double confinement of the strong metal-support interaction (SMSI) effect and carbon encapsulation, the well-stabilized Ni-ZnO-S3 catalyst was successfully synthesized. The size of Ni nanoparticles after calcination in the sequence of H 2 -N 2 mixture, air, and H 2 -N 2 mixture remained below 5 nm. Due to no significant size change in Ni nanoparticles, the prepared Ni-ZnO-S3 catalyst served well as model catalysts in the RWGS reaction, where the CO 2 conversion and CO yield increased proportionally to the Ni loading weight. According to the result of in-situ FTIR, an associative mechanism of RWGS reaction over Ni-ZnO-S3 was also identified. Therefore, this dual protect strategy provides a potential solution for building highly anti-sintering catalysts based on the colloidal synthesis route.
研究领域:
催化化学
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材料科学
✓ 已验证
产品关联
DOI
高影响因子
ADVANCED MATERIALS
·
2021
·Vol. 34
·期 6
·2108727
·
IF 30.849
Zhijie Zhu,Kai Feng,Chaoran Li,Rui Tang,Mengqi Xiao,Rui Song,Di Yang,Binhang Yan,Le He
Colloidal metal nanocrystals with uniform sizes, shapes, compositions, and architectures are ideal building blocks for constructing heterogeneous catalysts with well-defined characteristics toward the investigation of accurate structure–property relationships and better understanding of catalytic mechanism. However, their applications in high-temperature heterogeneous catalysis are often restricted by the difficulty in maintaining the high metal dispersity and easy accessibility to active sites under harsh operating conditions. Here, a partial-oxide-coating strategy is proposed to stabilize metal nanocrystals against sintering and meanwhile enable an effective exposure of active sites. As a proof-of-concept, controlled partial silica coating of colloidally prepared Pd 0.82 Ni 0.18 nanocrystals with the size of 8 nm is demonstrated. This partially coated catalyst exhibits excellent activity, selectivity, and stability, outperforming its counterparts with fully coated and supported structures, in reverse water gas shift (RWGS) catalysis particularly at high operating temperatures. This study opens a new avenue for the exploration of colloidal metal nanocrystals in high-temperature heterogeneous catalysis.
研究领域:
材料科学
·
催化化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2024
·
IF 13.3
Xing Yi,Yan Wang,Zongpeng Zou,Yuan He,Li Lv,Wenxiang Tang,Tao Zhang,Shengwei Tang
The microreactor coupled mini-channel microdroplets extraction and separation technology (MES) was developed by adding polyvinyl alcohol (PVA) into microdroplets, realizing the controllable synthesis of a series of mono-component and multi-component metal oxide nano particles (MONPs). A double-layer surfactant structure composed of Span20 (oil phase surfactant) and PVA (water phase surfactant) was designed as a barrier to intercept and collect the precipitated salt at the microdroplet interface, the addition of PVA reduces the loss of salt components during the extraction process from 41.7 wt% to 1.1 wt%. The size control of mono-component MONPs (CuO, Co 3 O 4 , and NiO) was achieved using MES method. Furthermore, in the application direction of preparing multi-component MONPs, the advantages of MES in preparing multi-component catalysts (Ni/CeO 2 ) were verified. TEM, XRD, H 2 -TPR, CO 2 -TPD, XPS, BET et al. characterizations have shown that Ni entered the lattice of CeO 2 during precipitation to form a Ni-O-Ce solid solution and was therefore highly dispersed in CeO 2 . Ni/CeO 2 -MES showed high CO 2 conversion and CO selectivity in reverse water gas shift (RWGS) testing compared to Ni/CeO 2 catalysts prepared by impregnation method which has excellent thermal stability and can maintain over 99 % CO selectivity even after 50 h of reaction at 600 °C. The MES method was proved to be an efficient synthesis technology for MONPs and can be extended to a variety of metal oxides catalysts.
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
危险品化学品经营许可证（带存储）