Catalysts
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2020
·Vol. 10
·期 9
·1037
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IF 3.52
Zhaoyu Wen,Jie Wu,Guangyin Fan
Hydrogen generation through ammonia–borane (AB) hydrolysis has been regarded as one of the most promising pathways to tap renewable green energy. The design and synthesis of highly effective catalysts toward hydrogen production from aqueous AB is of paramount significance. Here, the facile synthesis of Rh nanoparticles (NPs) immobilized on nanodiamond (nano-DA) and concomitant AB hydrolysis to produce hydrogen was successfully achieved. The in situ generated Rh/nano-DA exhibited excellent catalytic activity toward AB hydrolysis, with a high turnover frequency (TOF) value of 729.4 min−1at 25 °C and a low activation energy of 25.6 kJ mol−1. Moreover, the catalyst could be reused four times. The unique properties of DA with abundant oxygen-containing groups enable the homogeneous distribution of small and surface-clean Rh NPs on the nano-DA surface, which can supply abundant accessible active sites for hydrogen evolution from AB hydrolysis. This study demonstrated that nano-DA can be applied as an ideal matrix to deposit efficient Rh nanocatalyst toward hydrogen evolution reaction.Keywords:nanodiamond;ammonia–borane;hydrogen evolution;rhodium nanoparticles
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
Catalysts
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2019
·Vol. 9
·期 3
·215
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IF 3.444
Penghe Su,Ya Chen,Xiaotong Liu,Hongyuan Chuai,Hongchi Liu,Baolin Zhu,Shoumin Zhang,Weiping Huang
A simple and practical Rh-catalyzed hydroformylation of vinyl acetate has been synthesized via impregnation-calcination method using silicate nanotubes (MgSNTs) as the supporter. The Rh0(zero valent state of rhodium) was obtained by calcination. The influence of calcination temperature on catalytic performance of the catalysts was investigated in detail. The catalysts were characterized in detail by X-ray diffraction (XRD), transmission electron microscopy (TEM), X-ray photoelectron spectrometer (XPS), atomic emission spectrometer (ICP), and Brunauer–Emmett–Teller (BET) surface-area analyzers. The Rh/MgSNTs(a2) catalyst shows excellent catalytic activity, selectivity and superior cyclicity. The catalyst could be easily recovered by phase separation and was used up to four times.Keywords:silicate nanotubes;Rh;hydroformylation;vinyl acetate
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
ACS Applied Materials & Interfaces
·
2017
·
IF 7.504
Juan Bai,Shu-He Han,Rui-Li Peng,Jing-Hui Zeng,Jia-Xing Jiang,Yu Chen
Inspired by graphene, ultrathin two-dimensional nanomaterials with atomic thickness have attracted more and more attention because of their unique physicochemical properties and electronic structure. In this work, the atomically thick ultrathin Rh2O3 nanosheet nanoassemblies (Rh2O3-NSNSs) were obtained by oxidizing the atomically thick ultrathin Rh nanosheet nanoassemblies with HClO. For the first time, Rh-based nanostructures were used as the oxygen evolution reaction (OER) electrocatalyst in an alkaline medium. Surprisingly, the as-prepared Rh2O3-NSNSs displayed extremely improved catalytic activity and durability for the OER compared with those of the commercial Ir/C catalyst and most recently reported Ir-based electrocatalysts. The result indicated Rh-based nanostructures that have great promise to become a potential candidate for efficient OER electrocatalyst because of the similarity of Rh and Ir prices. These experimental results demonstrated the reasonable morphological control of Rh2O3 nanostructures could significantly improve their catalytic activity and durability during heterogeneous catalysis.
研究领域:
材料科学
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化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2021
·
IF 13.273
Zhongyao Duan,Kai Deng,Chunjie Li,Mei Zhang,Ziqiang Wang,You Xu,Xiaonian Li,Liang Wang,Hongjing Wang
Hydrogen evolution reaction (HER) from water electrolysis in alkaline and neutral media provides a possibility to produce pure hydrogen fuel on a large scale. Therefore, the exploration of highly efficient non-Pt HER electrocatalysts is of great significance. Herein, polyaniline (PANI)-coated mesoporous Rh film on Ni foam is controllably fabricated by a micelle-assisted replacement reaction and the subsequent surface modification. Profiting from the synergetic effect of interconnected mesoporous structure, high electrical conductivity of PANI and the modified electronic structure of Rh, the synthesized mRh@PANI film exhibits superior HER electrocatalytic activity and durability in alkaline and neutral electrolytes. To reach a current density of 50 mA cm −2 , low overpotentials of 37 and 69 mV are required in 1 M KOH and 1 M PBS solutions, respectively.
研究领域:
材料科学
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电化学
✓ 已验证
产品关联
DOI
高影响因子
ELECTROCHIMICA ACTA
·
2019
·
IF 5.383
Qian Dang,Fan Liao,Yuyang Sun,Shanshan Zhang,Hui Huang,Wen Shen,Zhenhui Kang,Yandi Shi,Mingwang Shao
Though noble metals play a key role in the clean energy research, their wide practical applications have been limited by the high cost and the scarce natural reserves. It is significant to decrease their usage and increase the active sites in the catalysis. Herein, Rh nanocrystals were grown on the surface of silicon quantum dots with the help of Si H bonds to obtain Rh Si composites, which combined with carbon quantum dots to fabricate Rh Si C nanocomposites . The silicon quantum dots limited the size of Rh and prevented the aggregation. The addition of carbon quantum dots greatly increased the electron transportation during the catalytic process. When the Rh Si C nanocomposites were applied as electrocatalysts for hydrogen evolution reaction (HER), the optimal one exhibits Pt-like HER performance (low Tafel slope of 26 mV·dec -1 and long-term stability) with the content of noble metal less than half of that in 20 wt% Pt/C. This work could put forward an effective avenue to develop high efficient and affordable electrochemical catalysts for HER.
研究领域:
材料科学
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能源化学
✓ 已验证
产品关联
DOI
高影响因子
Nature Communications
·
2016
·Vol. 7
·期 1
·1-7
·
IF 11.329
Zhu Lili,Lin Haiping,Li Youyong,Liao Fan,Lifshitz Yeshayahu,Sheng Minqi,Lee Shuit-Tong,Shao Mingwang
Currently, platinum-based electrocatalysts show the best performance for hydrogen evolution. All hydrogen evolution reaction catalysts should however obey Sabatier’s principle, that is, the adsorption energy of hydrogen to the catalyst surface should be neither too high nor too low to balance between hydrogen adsorption and desorption. To overcome the limitation of this principle, here we choose a composite (rhodium/silicon nanowire) catalyst, in which hydrogen adsorption occurs on rhodium with a large adsorption energy while hydrogen evolution occurs on silicon with a small adsorption energy. We show that the composite is stable with better hydrogen evolution activity than rhodium nanoparticles and even exceeding those of commercial platinum/carbon at high overpotentials. The results reveal that silicon plays a key role in the electrocatalysis. This work may thus open the door for the design and fabrication of electrocatalysts for high-efficiency electric energy to hydrogen energy conversion.
研究领域:
材料科学
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电化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
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2020
·
IF 3.573
Teng Li,Ping Jin,Yekai Zhang,Kexin Huang,Jingen Long,Jun Jiang,Shengqin Liu,Ayusman Sen,Weiran Yang
As an important biomass-derived chemical, d-sorbitol can be converted to a variety of useful chemicals and fuels. Because of the strong nucleophilicity of I– and reducibility of hydrogen iodide (HI), hydroiodic acid has been used for polyol hydrogenolysis with high selectivity. Here, d-sorbitol was converted by HI, rhodium, and hydrogen to give a high yield of iodohexanes (94.2%) at 373 K in a water/cyclohexane biphasic system. Rhodium and hydrogen were used to regenerate HI in situ. The reaction mechanism was studied in detail by using model molecules. The substitution–elimination–addition (SEA) mechanism was proven to be the most possible pathway. The high concentration of both proton and iodide was found to be necessary for the efficient conversion of d-sorbitol and the selective formation of iodohexanes. Besides, water could inhibit the conversion of d-sorbitol dramatically. These findings were explained by kinetic study and demonstrated in the reaction kinetic equation. This catalytic system, including HI and RhCl3, was proven to be reusable. In addition, iodohexanes can be quantitatively converted to hexenes over ZrO2 at 473 K.
研究领域:
化学工程
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生物质转化
✓ 已验证
产品关联
DOI
高影响因子
BRAZILIAN JOURNAL OF CHEMICAL ENGINEERING
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2023
·
IF 1.2
He Yuntao,Guo Xiaxin,Qiao Luyang,Ye Runping,Zong Shanshan,Cao Xinyi,Cheng Jiankai,Zhou Zhangfeng,Yao Yuangen
Rh complexes are considered as the most promising catalysts for formaldehyde hydroformylation since they can achieve higher yields of glycolaldehyde under mild conditions. Although heterogeneous catalysts are convenient to separate, Rh-based heterogeneous catalysts usually have limited catalytic activity in hydroformylation of formaldehyde. Here, four different supports (Al 2 O 3 , SiO 2 , SBA-15 and HMS), loaded with Rh by impregnation method, have been developed for formaldehyde hydroformylation. The physico-chemical properties of the materials have been investigated by means of complementary techniques. Due to the presence of more oxidized rhodium species and stronger metal support interactions, the silica-based catalysts achieved higher formaldehyde conversion and glycolaldehyde selectivity than Rh/Al 2 O 3 . Moreover, SBA-15 and HMS zeolites were synthesized by adjusting the structure of the silica support. Thus, the selectivity of 94.8% for glycolaldehyde and a remarkable glycolaldehyde yield of 52.7% over Rh/SBA-15 catalyst was obtained due to its larger surface area, suitable pore structures and higher dispersion of Rh species.
研究领域:
化学工程
·
催化材料科学
✓ 已验证
产品关联
DOI
高影响因子
ChemCatChem
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2024
·
IF 3.8
Qi Yang,Ying Zheng,Yi Feng,Jie Ding,Maoshuai Li,Shouying Huang,Mei-Yan Wang,Xinbin Ma
Graphical Synergy between Rh 0 and Rh + on the Rh clusters is essential to catalyze heterogeneous formaldehyde hydroformylation. Rh 0 works as the adsorption/activation site for formaldehyde and hydrogen. Rh + works as the coordination site for CO and PPh 3 . The formed Rh─CH 2 OH* intermediate is responsible for the highly selective hydroformylation to glycolaldehyde. Controlling the metal geometric and electronic structure is of significance in developing efficient catalysts for heterogeneous hydroformylation. This study examines the structural sizes of Rh and Rh + -Rh 0 distribution to construct a highly active catalyst for formaldehyde hydroformylation. The active sites for hydroformylation require several Rh n atoms, while single-atom Rh can solely catalyze hydrogenation. The highest activity was achieved on Rh nanoclusters (0.95 nm), giving a TOF of 191 h −1 and selectivity of 82% for glycolaldehyde formation. The tunability of the electronic properties of Rh nanoclusters and the synergistic interaction between Rh + and Rh 0 are essential for enhanced activity. Pseudo- in situ FT-IR analysis elucidated that formaldehyde adsorbed on Rh nanocluster prefers to produce glycolaldehyde via hydroformylation, while formaldehyde adsorbed on isolated Rh δ+ sites tends to form methanol via hydrogenation. This study provides a new insight into the design of heterogeneous catalysts and guidance for understanding the reaction mechanism for aldehydes/olefins hydroformylation.
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
ACS Applied Nano Materials
·
2024
·
IF 5.3
Guanghui Yang,Hugang Zhang,Jiarong Li,Yile Wang,Kai Deng,Hongjie Yu,Hongjing Wang,Ziqiang Wang,Liang Wang
It is important to achieve sustainable ammonia production under mild conditions, and the electrocatalytic nitrogen reduction reaction (NRR) is a promising strategy. However, the precise construction of highly active NRR electrocatalysts for ammonia synthesis remains challenging. Here, we construct B-doped PdRh mesoporous nanotubes (B-PdRh MNTs) as efficient NRR electrocatalysts. The mesoporous nanotubular structure provides abundant active sites, and B doping enhances the adsorption energy of N2. As such, the NH3 yield and Faraday efficiency of B-PdRh MNTs reach 12.03 μg h–1 mgcat–1 and 16.28% under 0.1 M Na2SO4, respectively. This work provides strategies for B-doped catalysts for efficient electrocatalytic NRR applications.
研究领域:
材料科学
·
电化学
✓ 已验证
产品关联
DOI
高影响因子
Journal of Materials Chemistry A
·
2024
·
IF 10.7
Ben Zhang,Yijuan Zheng,Zhenyu Xing,Zihe Wu,Chong Cheng,Tian Ma,Shuang Li
Designing and synthesizing eco-friendly and efficient catalysts for the hydrogen evolution reaction (HER) plays a crucial role in the field of large-scale and high-purity hydrogen production. However, it is severely hampered by the sluggish kinetics of the water dissociation step in non-acidic media. To optimize catalytic kinetics, interfacial electron engineering between active sites and supports has been regarded as an essential strategy to achieve compelling electrocatalytic all-pH-value-hydrogen production. Herein, we present the successful fabrication of WNO-coupled Rh layers (Rh–WNO) by a simple thermal treatment of a urea sol–gel with mixed W and Rh salts. This facile one-pot synthetic method is easy to scale up and the resulting Rh–WNO catalyst features Rh nanoclusters anchored on the surface of the well-ordered WNO crystals via Rh–N and Rh–O bonds. The optimal catalyst, Rh–WNO, delivered low overpotentials of 19, 22, and 134 mV at a current density of 10 mA cm−2 in 0.5 M H2SO4, 1.0 M KOH, and 1.0 M PBS, respectively. Notably, Rh–WNO exhibits a high turnover frequency (TOF) of 7.84 H2 s−1 in alkaline conditions, which is much higher than those of Pt/C (0.9 H2 s−1), Rh/C (0.77 H2 s−1), and most of the reported HER electrocatalysts. This work may provide an effective and economic approach for scaling up the production of highly efficient and stable metal nitride-based HER catalysts.
研究领域:
材料科学
·
能源化学
✓ 已验证
DOI
高影响因子
JOURNAL OF CATALYSIS
·
2021
·
IF 7.92
Weikang Dai,Maoshuai Li,Jie Wei,Qi Yang,Yi Feng,Cheng Yang,Wanxin Yang,Mei-Yan Wang,Xinbin Ma
The aldehyde hydroformylation is of critical importance for synthesis of higher aldehydes and polyhydric alcohols, but the reaction mechanism has not been clearly resolved in the existing literature. In this paper, we have established the dissociation and anion mechanism for formaldehyde hydroformylation using DFT calculation and experimental study. In the dissociation mechanism, HCHO insertion into the Rh-H bond is the rate-controlling step and CH 3 OH, HCOOCH 3 are preferentially produced via the CH 3 O-Rh route. The CO coordination reaction of CH 3 O-Rh(CO) 2 (PPh 3 ) is not favored energetically leading to facile generation of CH 3 OH relative to HCOOCH 3 . In the anion mechanism, the nucleophilic addition of HCHO to the HOCH 2 -Rh species is more energetically favorable and the rate-determining step turns to H 2 oxidation addition. The effective energy barrier of hydrogenolysis for CH 3 OH is higher than that for HOCH 2 CHO, accounting for higher selectivity of HOCH 2 CHO than CH 3 OH observed in the reaction. The calculations also predict the strong electron-donating ligand serves to give rise to higher reactivity in the anion mechanism.
研究领域:
化学
·
催化反应
✓ 已验证
DOI
高影响因子
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