Asian Journal of Organic Chemistry
·
2017
·Vol. 7
·期 1
·240-247
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IF 2.788
Rui Yan,Zhong-Xia Wang
Graphical Oxidative coupling of allylic alcohols : [Cp*RhCl 2 ] 2 was demonstrated to catalyze the oxidative coupling of alkenylpyridines with allylic alcohols through alkenyl C−H activation in the presence of AgOTf and AgOAc to afford β-alkenyl ketones and aldehydes in moderate to good yields. [Cp*RhCl 2 ] 2 was demonstrated to catalyze the oxidative coupling of alkenylpyridines with allylic alcohols through alkenyl C−H activation in the presence of AgOTf and AgOAc to afford β-alkenyl ketones and aldehydes in moderate to good yields. Allylic alcohol, 1-aryl and 1-alkyl allylic alcohols can be coupled with various alkenylpyridines. The reaction occurred at the γ-position of allylic alcohols and the cis -β-position of the alkenylpyridines.
研究领域:
有机化学
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催化化学
✓ 已验证
DOI
高影响因子
Journal of Physical Chemistry C
·
2021
·
IF 4.126
Fuyong Zhang,Wei Zhou,Xuewei Xiong,Yuhao Wang,Kang Cheng,Jincan Kang,Qinghong Zhang,Ye Wang
Catalytic transformation of CO2 into chemicals in large demand such as ethanol has attracted much research attention under the background of establishing carbon-neutral societies. Supported Rh catalysts are promising candidates for the hydrogenation of CO2 to ethanol but suffer from low ethanol productivity and poor catalyst stability. Here, we report that zeolite silicalite-1 embedded Na-promoted Rh nanoparticles (Na-Rh@S-1) demonstrate high productivity and stability for CO2 hydrogenation to ethanol. The ethanol selectivity of 24% was attained at a CO2 conversion of 10%, and the space-time yield of ethanol reached 72 mmol gRh–1 h–1, which outperformed most of the Rh-based catalysts reported to date. While a reference catalyst prepared by impregnation underwent deactivation, the Na-Rh@S-1 catalyst was stable for at least for 100 h owing to the confinement effect. The Na+ modifier played crucial roles in enhancing the CO2 conversion and ethanol selectivity by suppressing methane formation. The characterizations suggest that the presence of Na+ enables the coexistence of Rh0 and Rh+ and enhances CO2 adsorption, thus boosting ethanol formation. A comparative study between CO and CO2 hydrogenation reveals that the Na-Rh@S-1 catalyst is significantly more active and selective toward CO2 hydrogenation to ethanol.
研究领域:
催化化学
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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
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
·
2022
·
IF 7.139
Zi-Hao Zhang,Lin-Chang Liu,Chen-Xi Zhang,Hong-Lin Zhu,Yue-Qing Zheng
Alloy catalyst has been widely studied and used for hydrolytic dehydrogenation of ammonia borane (NH 3 BH 3 , AB) with excellent catalytic performance due to the synergistic effect of bimetal . Herein, a series of Rh 1-x Co x /Ni@Ni–N–C catalysts were prepared by an impregnation reduction method. The optimized Rh 0.75 Co 0.25 /Ni@Ni–N–C catalyst exhibited good catalytic performance with turnover frequency of 223.08 mol H2 mol cat −1 min −1 at 303 K, but decreased the catalytic performance compared with Rh/Ni@Ni–N–C. According to the XPS and Raman analysis, the RhCo alloy nanoparticles could be loaded at the defect position of Ni@Ni–N–C, and the Co nanoparticles occupied the intercalation between Rh and the defective site of the carrier, which could weaken the catalytic activity of AB hydrolysis. Based on the above research, we proposed the catalytic mechanism of the activation of the RhCo–H species. This work provides a new strategy for designing alloy-supported nano-catalysts.
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
CHEMICAL ENGINEERING RESEARCH & DESIGN
·
2023
·
IF 3.9
Dongxue Tao,Haitao Zhou,Kaihui Cui,Linchen Xie,Kun Huang
The unique characteristics of the interface environment that distinguish bulk phases can promote or inhibit certain reactions and significantly change chemical reactivity. In this work, the separation of Rh (III) and Fe (III) on the surface of concentrated hydrochloric acid was studied by a thin-layer oil membrane (TOM) extraction based on laminar flow with 18-Crown-6-ether (18C6) as the extractant. A new phenomenon different from conventional extraction was found. The TOM extraction prefers to identify hydrated Rh (III) anions rather than H 3 O + ions at the interface due to a lower concentration of free hydrated hydrogen ions on the surface of concentrated hydrochloric acid. However, during the conventional extraction, the H 3 O + ions in the bulk phase are preferentially extracted by the 18C6, and then the hydrated rhodium (III) anions could be extracted by the protonated crown ether through the ion association mechanism. Besides, it was found that the TOM extraction could enhance extraction of hydrated rhodium (III) anions by taking advantage of the uniqueness of rhodium species on the interface, and by adjusting the thickness of the oil membrane and the flow rate of the aqueous phase . The decrease in the oil membrane thickness and the increase in the flow rate of the aqueous phase are conducive to the complexation of 18C6 with the hydrated rhodium (III) at the interface, which can better reflect the targeting and the controllability of extracting single species of hydrated rhodium (III) ions at the interface. Considering the applications of selective recovery of Rh (III) from concentrated hydrochloric acid leaching solution of waste automobile catalyst, the selective separability of Rh (III) to other coexisting metal impurity ions such as Fe (III), Cu (II), Co (III) and Ni (II), was also evaluated. This work provides a new strategy for preferential recovery and separation of rhodium in concentrated hydrochloric acid leach solutions containing other base metal ions for possible future's application.
研究领域:
化学工程
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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
IONICS
·
2023
·Vol. 29
·期 5
·1991-2003
·
IF 2.8
Yuhui Cui,Jinghao Lu,Lijuan Yang,Zheng Hao,Runjin Wu,Qian Li,Shijia Xu,Libin Yang
In proton exchange membrane fuel cells (PEMFCs), the most advanced catalysts are mainly carbon loaded with platinum (Pt), but the cathodic catalytic active center is too low to match the oxidation activity and rate at the anode. Co atoms doped into the lattice of Pt alloy change the electronic structure of platinum and reduce the binding energy of oxygen atoms. Au or Rh atoms embedded into the lattice of Pt 3 Co alloy compensate the defect and enhance the activity and rate of the oxygen reduction. Through base on density functional theory (DFT), the adsorption energy for oxygen on Pt 3 Co, Au-Pt 3 Co, and Rh-Pt 3 Co and the segregation energy of Co atoms were calculated. The results show that Au or Rh doped weakens the binding energy of Pt for oxygen on the Pt 3 Co alloy and improves the activity and stability of oxygen reduction. Compared with Rh, the introduction of Au element shows better effects in the electrocatalytic reaction process. Graphical Abstract
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 CHEMICAL SCIENCES
·
2024
·Vol. 136
·期 1
·1-9
·
IF 1.7
Zhang Mingyu,Yan Dong,Xu Rui,Tang Yuqi,Xu Shuangping,Qu Yanqing,Xu Jingyu,Du Boyu,Jia Hongge
A new rhodium complex [Rh(cod)(TTT) 2 ] was synthesized by [Rh(cod)Cl] 2 as a precursor, and 4,4',4''-(1,3,5-triazine-2,4,6-triyl)trianiline (TTT) as a ligand. Its structure was verified by 1 H and 13 C NMR. The results indicate that the complex shows high activity in phenylacetylene polymerization. It was applied to the polymerization of phenylacetylene with a yield of 45.0% and Mw = 2.26×10 5 at ultra-low rhodium feed ratio ([Rh.]/[M.]=1/60000). Graphical abstract A new rhodium complex [Rh(cod)(TTT) 2 ] was synthesized by [Rh(cod)Cl] 2 as a precursor, and 4,4',4''-(1,3,5-triazine-2,4,6-triyl)trianiline (TTT) as a ligand. It was applied to the polymerization of phenylacetylene with a yield of 45.0% and Mw = 2.26×10 5 at ultra-low rhodium feed ratio ([Rh.]/[M.]=1/60000
研究领域:
无机化学
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有机金属化学
·
高分子化学
·
催化
✓ 已验证
DOI
高影响因子
Inorganic Chemistry Frontiers
·
2025
·
IF 6.4
Guangxia Wang,Wenhui Wang,Yaozhong Yu,Tao Hu,Juan Ding,Yongming Sui
Active and durable catalysts are crucial for the hydrogen evolution reaction (HER). In the volcano plot, rhodium (Rh) and platinum (Pt) are positioned closely, while the activity and stability of Rh are much inferior to those of Pt. Here, we developed a Rh/TiO2/Ti electrocatalyst to mitigate Pt dependency. The in situ formed TiO2 with oxygen vacancies was prepared utilizing Ti foam as the Ti source. The TiO2 support can confine Rh nanoparticles and ensure charge accumulation at the Rh site, while Rh can enhance the conductivity of TiO2. DFT calculations demonstrate that the strong interaction between Rh and TiO2 could regulate the electronic structure of Rh, thereby accelerating water dissociation and optimizing the adsorption strength of *H. Consequently, compared to Rh/Ti, Rh/TiO2/Ti exhibits significantly enhanced HER activity, requiring overpotentials of only 37.3 and 34.3 mV to reach 10 mA cm−2 in the alkaline and acidic HER, respectively. Furthermore, the vertical nanoarray structure, surface roughness, and metal–support interaction endow Rh/TiO2/Ti with remarkable durability. It works in both alkaline and acidic media for 120 hours at 10 mA cm−2 with unnoticeable activity decline, outperforming commercial Pt/C. This work provides a strategy to overcome the activity and stability limitations of Rh-based catalysts, providing references for promising catalysts for water electrolysis.
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
APPLIED CATALYSIS B-ENVIRONMENTAL
·
2020
·
IF 16.683
Zhiwei Chen,Yuyu Bu,Lin Wang,Xiao Wang,Jin-Ping Ao
In this paper, we prepare porous g-C 3 N 4 by hydrothermal process, and then Rh atoms are anchored on the carbon nitride framework. After further phosphating, a novel single-sites-like Rh-phosphide (Rh-P) modified carbon nitride photocatalyst is fabricated. The photocatalytic hydrogen evolution rate of Rh-P modified carbon nitride is 33 times higher than that of pure C 3 N 4 . Structure analysis results show that Rh-P dots are dispersed with single-sites state on the surface of carbon nitride framework. Further theoretical calculation and the photoelectrochemical results reveal that Rh-P single-sites on carbon nitride provide photogenerated convergence centers to decrease the hydrogen evolution potential and enhance the free charge transfer capability. Thus, it improves the photocatalysis hydrogen evolution performance of the carbon nitride.
研究领域:
材料科学
·
光催化
·
化学
✓ 已验证
DOI
高影响因子
Research
·
2021
·
IF 0
Yuqing Cheng,Jiafu Shi,Yizhou Wu,Xueying Wang,Yiying Sun,Ziyi Cai,Yu Chen,Zhongyi Jiang
Solar-driven photocatalytic regeneration of cofactors, including reduced nicotinamide adenine dinucleotide (NADH), reduced nicotinamide adenine dinucleotide phosphate (NADPH), and reduced flavin adenine dinucleotide (FADH2), could ensure the sustainable energy supply of enzymatic reactions catalyzed by oxidoreductases for the efficient synthesis of chemicals. However, the elevation of cofactor regeneration efficiency is severely hindered by the inefficient utilization of electrons transferred on the surface of photocatalysts. Inspired by the phenomenon of ferredoxin-NADP+ reductase (FNR) anchoring on thylakoid membrane, herein, a homogeneous catalyst of rhodium (Rh) complex, [Cp∗Rh(bpy)H2O]2+, was anchored on polymeric carbon nitride (PCN) mediated by a tannic acid/polyethyleneimine (TA/PEI) adhesive layer, acquiring PCN@TA/PEI-Rh core@shell photocatalyst. Illuminated by visible light, electrons were excited from the PCN core, then transferred through the TA/PEI shell, and finally captured by the surface-anchored Rh for instant utilization during the regeneration of NADH. The TA/PEI-Rh shell could facilitate the electron transfer from the PCN core and, more importantly, achieved ~1.3-fold elevation of electron utilization efficiency compared with PCN. Accordingly, the PCN@TA/PEI-Rh afforded the NADH regeneration efficiency of 37.8% after 20 min reaction under LED light (405 nm) illumination, over 1.5 times higher than PCN with free Rh. Coupling of the NADH regeneration system with formate dehydrogenase achieved continuous production of formate from carbon dioxide (CO2). Our study may provide a generic and effective strategy to elevate the catalytic efficiency of a photocatalyst through intensifying the electron utilization.
研究领域:
生物化学
·
光催化材料科学
✓ 已验证
DOI
Chemistry-An Asian Journal
·
2020
·Vol. 15
·期 20
·3356-3364
·
IF 4.056
Kai Liu,Zixi Lyu,Xuejiao Chen,Xinyan Liao,Guanhong Chen,Xin Lin,Wei Wang,Shuifen Xie
Graphical A selective synthesis of atypical Rh−Pt alloyed nanocrystals with different morphologies and defective structures has been achieved through kinetically manipulating the nucleation and nucleus attachment. The defective Rh 47 Pt 53 wavy nanowires endowed with abundant grain boundaries and twin boundaries present a superior electrocatalytic performance for the ethanol oxidation reaction. Defective metal nanostructures have attracted great attention due to the striking catalytic behavior of the defect sites. Atypical metal nanocrystals generated from attached nuclei can accommodate abundant grain boundaries (GBs) and twin boundaries (TBs). However, the understanding of their growth-mechanism and precisely synthetic control over such defective nanocrystals are still scarce. Herein, using the Rh−Pt nanoalloy as a model system, we systematically demonstrate that a prudent control of the reaction kinetics can manipulate the metal nucleation and nucleus attachment to create atypical nanocrystals, including small isolated nanoparticles (NPs), defect-rich wavy nanowires (WNWs), and {100} facet-bounded spliced nanocubes (SNCs). In the ethanol oxidation electrocatalysis, the Rh 47 Pt 53 WNWs featured with abundant TBs and GBs show the greatest mass activity (0.655 A ⋅ mg −1 Pt , 2.9 times to the commercial Pt/C) and durability. Our work captures the core of reaction kinetics on regulating the nucleus attachment and enables the rational control over the nanocrystal morphology and defect.
研究领域:
材料科学
·
化学工程
·
纳米技术
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Journal of Materials Chemistry A
·
2020
·Vol. 8
·期 22
·11442-11447
·
IF 11.301
Qinglin Liu,Yinle Li,Yanan Fan,Cheng-Yong Su,Guangqin Li
Selective hydrogenation of α,β-unsaturated aldehydes to achieve high selectivity towards a desirable product is still a great challenge mainly because of the complex conjugate system. Herein, Rh nanoclusters encapsulated in MIL-101 (Cr), synthesized by the double solvent method, are able to selectively hydrogenate CC of cinnamaldehyde, an α,β-unsaturated aldehyde and achieve over 98% selectivity with a conversion of 98% to a saturated aldehyde under mild conditions. Fourier transform infrared spectroscopy confirms that MIL-101 acts as an aldehyde protector to suppress the reactivity of CO, and the X-ray photoelectron spectroscopy (XPS) data indicate that the electropositive Rh, owing to the electron transfer from Rh to MIL-101, preferentially absorbs CC rather than CO leading to improvement of the selectivity towards saturated aldehydes. In addition, Rh@MIL-101 can also efficiently catalyse hydrodefluorination of aryl fluorides with good stability. This work provides a basic strategy to develop other selective heterogeneous catalysts via structural modulation for synergetic catalysis.
研究领域:
催化化学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
Journal of Materials Chemistry A
·
2020
·Vol. 8
·期 25
·12378-12384
·
IF 11.301
Fang Luo,Long Guo,Yuhua Xie,Jingxiang Xu,Weiwei Cai,Konggang Qu,Zehui Yang
Efficient electrocatalysts for the hydrogen evolution reaction (HER) in both acidic and alkaline media are prominently important to advance the widespread application of industrial water splitting technology. In this work, we have synthesized ultrasmall rhodium–rhodium phosphide hetero-nanoparticles (3.4 nm, Rh–Rh2P@C) by partial phosphorization of Rh@C at 300 °C together with Na2HPO2. The constructed Rh–Rh2P@C requires only 24 mV and 37 mV overpotentials to reach 10 mA m−2 in 0.5 M H2SO4 and 1 M KOH electrolytes, which are lower than those of Rh@C and Rh2P@C due to the formation of heterointerfaces inducing modulation of local electronic structures and more active sites; as a result, a more moderate hydrogen adsorption–desorption strength is achieved for Rh–Rh2P@C as proved by theoretical calculation. Moreover, the calculated mass activity of Rh–Rh2P@C is 4 orders of magnitude higher than that of the benchmark Pt/C electrocatalyst. Besides, exceptional stability is recorded for Rh–Rh2P@C in both acidic and alkaline electrolytes due to the strong electronic interaction between Rh and Rh2P. This study offers a new strategy to manufacture efficient electrocatalysts for various applications.
研究领域:
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
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