Small
·
2024
·
IF 13
Songzhu Xing,Xujiao Ma,Qingqing Gu,Nana Ma,Zhong Zhang,Guoying Han,Rui Huang,Xiao Feng,Bing Yang,Chunying Duan,Yiwei Liu
The construction of defective sites is one of the effective strategies to create high-activity Metal–Organic frameworks (MOFs) catalysts. However, traditional synthesis methods usually suffer from cumbersome synthesis steps and disordered defect structures. Herein, a cluster–cluster co-nucleation (CCCN) strategy is presented that involves the in situ introduction of size-matched functional polyoxometalates (H 6 P 2 W 18 O 62 , {P 2 W 18 }) to intervene the nucleation process of cluster-based MOFs (UiO-66), achieving one-step inducement of exposed defective sites without redundant post-processing. POM-induced UiO-66 ({P 2 W 18 }-0.1@UiO-66) exhibits a classical reo topology for well-defined cluster defects. Moreover, the defective sites and the interaction between POM and skeletal cluster nodes are directly observed by Integrated Differential Phase Contrast in Scanning Transmission Electron Microscopy (iDPC-STEM). Owing to the molecular-level proximity between defective sites and POM in the same nano-reaction space, {P 2 W 18 }-0.1@UiO-66 exhibits efficient tandem catalysis in the preparation of γ-valerolactone (γ-GVL) from laevulinic acid (LA) by the combination of Lewis and Brønsted acids with 11 times higher performance than defective UiO-66 formed by conventional coordination modulation strategy. The CCCN strategy is applicable to different POM and has the potential to be extended to other cluster-based MOFs, which will pave a new way for the construction of functional MOFs with multi-centered synergistic catalysis.
研究领域:
材料科学
·
催化化学
✓ 已验证
DOI
PubMed
高影响因子
ACS Catalysis
·
2014
·
IF 7.572
Le Xu,Chen-geng Li,Kun Zhang,Peng Wu
Tandem catalysis has been realized on the multilayered zeolites with organic-structure-directing agent (OSDA) molecules occluded within micropores. A combination of mild acid treatment and ion-exchange with ammonia solution was carried out on as-synthesized multilamellar MFI aluminosilicate, giving rise to an acid–base bifunctional catalyst. Containing tripropyl head groups, the Gemini-type quaternary ammonium OSDAs were firmly immobilized in the intersection of straight and sinusoidal 10-membered ring channels, with the other one exposed to the layer surface of the nanosheets. The resulting organic–inorganic materials possessed simultaneously the acid sites related to the framework Al and the base sites derived from coexisting OSDAs. In particular, two types of base sites were present, that is, the Lewis base sites due to the SiO– species and Brønsted base sites due to the OH– counteranion of exposed quaternary ammonium cations. The rigid materials were highly active and reusable in the one-pot reaction of tandem deacetalization–Knoevenagel condensation. Supporting palladium nanoparticles (Pd NPs) on the organic–inorganic hybrid zeolite led to bifunctional catalysts, which catalyzed effectively one-pot synthesis of benzylidene malononitrile from benzyl alcohol under soluble-base-free conditions, in which the benzyl alcohol was first aerobic oxidized to intermediate benzaldehyde followed by Knoevenagel condensation with malononitrile.
研究领域:
材料化学
·
催化化学
✓ 已验证
DOI
高影响因子
FUEL
·
2024
·
IF 6.7
Weizuo Li,Qiang Li,Zhenhao Xiao,Shu Shang,Dafang He,Xin Wang,Haiqun Chen
The auricularia auricula (termed as AA), which is regarded as a specific natural resource due to its strong swelling characteristic. However, the weak water solubility of bimetallic organic frameworks (bi-MOFs) has not allowed it to be a well guest component to encapsulate into the cell walls of AA. So finding a water-soluble bi-MOFs to encapsulate into AA is the key to prepare the highly dispersed alloy catalyst for heterogeneous catalytic reactions. Therefore, a bi-metallic water-soluble NiCo MOFs (named as NiCo- hmta ) encapsulated into AA (termed NiCo- hmta @AA) composite via chemical interaction was synthesized. Subsequently, a nitrogen-doped carbon confined NiCo alloy catalyst (named as NiCo@CN- hmta -CA) derived from NiCo- hmta @AA composite was prepared. The developed NiCo@CN- hmta -CA exhibited superior performance for tandem catalytic nitroarenes with alcohols in comparison with classic NiCo/CN- hmta -PA (pyrolysis of composite towards AA derived CN supported NiCo- hmta ), NiCo@CN- hmta (direct pyrolysis of NiCo- hmta ) catalysts. Various characterizations (e.g. XRD, SEM, HADDF-STEM) were conducted to explore the origin improvement of NiCo@CN- hmta -CA catalyst for tandem catalytic nitroarenes with alcohols. The strategy, natural resource encapsulated MOFs materials, was employed in this work may open up a new avenue for the design and synthesis of highly dispersed alloy catalysts for other heterogeneous catalytic reactions.
研究领域:
催化化学
·
材料科学
✓ 已验证
DOI
高影响因子
Joule
·
2019
·
IF 0
Man Yang,Haifeng Qi,Fei Liu,Yujing Ren,Xiaoli Pan,Leilei Zhang,Xiaoyan Liu,Hua Wang,Jifeng Pang,Mingyuan Zheng,Aiqin Wang,Tao Zhang
Cellulosic ethanol is one of the most important biofuels, yet its commercial production is hindered by the low-efficiency and high-cost bioconversion process. Here, we report a new chemocatalytic approach for the one-pot production of cellulosic ethanol. With a multifunctional Mo/Pt/WO x catalyst, cellulose is directly converted to ethanol in a one-pot reaction with a yield as high as 43.2 C%. Kinetic analysis reveals that such a one-pot process involves tandem catalysis from cellulose to ethylene glycol (rapid) followed by hydrogenolysis of ethylene glycol to ethanol (slow). Characterizations show that isolated and low-coordinated MoO x bonds to metallic Pt particles on the mesoporous WO x support, constituting x OMo–Pt–WO x interfacial sites, which offer high activity for C–O cleavage of ethylene glycol.
研究领域:
化学工程
·
可再生资源与环境科学
✓ 已验证
DOI
Nano Research
·
2024
·Vol. 17
·期 6
·4815-4824
·
IF 9.5
You Xingchao,Xu Jiawei,Zhuang Zechao,Xia Junkai,Wang Suwen,Wei Haiyan,Li Yongfu,Cai Yanjiang,Xiang Hai,Yu Bing
Developing electrocatalysts that exhibit both high activity and ammonia selectivity for nitrate reduction is a significant and demanding challenge, primarily due to the complex nature of the multiple-electron reduction process involved. An encouraging approach involves coupling highly active precious metals with transition metals to enhance catalytic performance through synergy. Here, we report a ruthenium-nickel alloy catalyst with nanosheets (Ru-Ni NSs) structure that achieves a remarkable ammonia Faradaic efficiency of approximately 95.93%, alongside a yield rate of up to 6.11 g·h −1 ·cm −2 . Moreover, the prepared Ru-Ni NSs exhibit exceptional stability during continuous nitrate reduction in a flow reactor for 100 h, maintaining a Faradaic efficiency of approximately 90% and an ammonia yield of 37.4 mg·L −1 ·h −1 using 0.05 M nitrate alkaline electrolyte. Mechanistic studies reveal that the catalytic process follows a two-step pathway, in which HONO serves as a migration intermediate. The presence of a partially oxidized Ru (002) surface enhances the adsorption of nitrate and facilitates the release of the migration intermediate by adjusting the strength of the electrostatic and covalent interactions between the adsorbate and the surface, respectively. On the other hand, the Ni (111) surface promotes the utilization of the migration intermediate and requires less energy for NH 3 desorption. This tandem process contributes to a high catalytic activity of Ru-Ni NSs towards nitrate reduction.
研究领域:
电化学
·
催化
·
纳米材料
·
环境化学
·
能量转换
·
材料科学
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）