INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
·
2019
·
IF 4.084
Junfang Ding,Liping Li,Ye Wang,Xianzhe Xu,Shaoqing Chen,Xiyang Wang,Huixia Li,Shuaiqiang Zhao,Guangshe Li
Precious metal nanoparticles , widely used as heterogeneous catalysts , are easy to aggregate and deactivate, restricting their applications in many important catalytic fields like preferential CO oxidation (CO-PROX) in H 2 -rich stream. In this work, well dispersed Rh nanoclusters anchored on CaCO 3 @biocarbon derived from waste eggshell (ESMC) were synthesized through a step carbonization and incipient wetness impregnation process. The obtained catalysts exhibited 3D macroporous architecture, which is favorable for exposure of more nucleation sites of precious metal Rh, thus minimizing the aggregation of Rh particles. Furthermore, a thick carbon shell attached to eggshells, with interesting electronic structure and surface chemistry, efficiently transfers electrons between Rh and biocarbon@CaCO 3 support, and enhances the interaction between Rh NPs and support. Both effects synergistically allow Rh/ESMC to equip more active adsorption sites-asymmetric Rh(CO) 2 gem-dicarbonyl, thus greatly promoting the catalytic performance of Rh/ESMC in CO-PROX (operation temperature window: 140–240 °C). The present finding offers an environmentally friendly approach to fabricate well dispersed Rh nanoclusters catalysts, and it can be extended to rationally design other supported metal nanoparticle catalysts.
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
·
2018
·
IF 4.229
Jiaqin Chen,Min Hu,Mei Ming,Caili Xu,Yi Wang,Yun Zhang,Jiangtao Wu,Daojiang Gao,Jian Bi,Guangyin Fan
Hydrogen generation from the hydrolysis of ammonia borane (AB) over heterogeneous catalysts is essential for practical applications. Herein, efficient hydrogen evolution from AB hydrolysis over the carbon-supported Rh nanoparticles synthesized with sodium citrate (Rh/C-SC) was achieved at 25 °C. The turnover frequency value of Rh/C-SC was 336 mol H 2 (mol Rh min) −1 , whereas that of Rh/C catalyst only yielded a value of 134 mol H 2 (mol Rh min) −1 . The improvement of the catalytic performance of Rh/C-SC catalyst could be attributed to the small Rh particles with highly active surface areas, which were prepared by using sodium citrate as the stabilizing agent. This result indicates that sodium citrate can be applied as a useful stabilizing agent for synthesizing active metal nanoparticles , thus highly promoting the practical application of AB system for fuel cells.
研究领域:
化学
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材料科学
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能源研究
✓ 已验证
产品关联
DOI
高影响因子
RSC Advances
·
2023
·Vol. 13
·期 20
·13985-13990
·
IF 3.9
Changhui Jin,Ruijing Fu,Longqiao Ran,Wenhui Wang,Fuxin Wang,Dezhou Zheng,Qi Feng,Guangxia Wang
Rational design of efficient and stable electrocatalysts for the hydrogen evolution reaction (HER) has attracted wide attention. Noble metal-based electrocatalysts with ultrathin structures and highly exposed active surfaces are essential to boost the HER performance, while the simple synthetic strategies remain challenging. Herein, we reported a facile urea-mediated method to synthesize hierarchical ultrathin Rh nanosheets (Rh NSs) without using toxic reducing agents and structure directing agents in the reaction. The hierarchical ultrathin nanosheet structure and grain boundary atoms endow Rh NSs with excellent HER activities, which only requires a lower overpotential of 39 mV in 0.5 M H2SO4 compared to the 80 mV of Rh nanoparticles (Rh NPs). Extending the synthesis method to alloys, hierarchical ultrathin RhNi nanosheets (RhNi NSs) can be also obtained. Benefiting from the optimization of electronic structure and abundant active surfaces, RhNi NSs only require an overpotential of 27 mV. This work provides a simple and promising method to construct ultrathin nanosheet electrocatalysts for highly active electrocatalytic performance.
研究领域:
材料科学
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电化学
·
纳米技术
✓ 已验证
产品关联
DOI
PubMed
高影响因子
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
·
2021
·
IF 5.816
Junlu Bi,Xuejun Zhai,Guishan Liu,Jing-Qi Chi,Xuanyi Wang,Shaojin Chen,Zhenyu Xiao,Lei Wang
Searching for highly efficient and Pt-free electrocatalysts with comparable hydrogen evolution reaction (HER) activities to the benchmark Pt/C catalyst is highly demanded for developing renewable water electrolysis system but still remains challenging. In the current work, low loading of P modified ultrafine Rh nanoparticles encapsulated in N, P dual-doped carbon layers (Rh–P@NPC) have been prepared through a facile polymerization-impregnation followed by high-temperature pyrolysis process . Benefiting from the unique core-shell structural advantages and synergistic effect of Rh–P and NPC components, the resulting Rh–P@NPC catalyst not only exhibits remarkable electrocatalytic activity for HER in the whole pH range with a low overpotential of 31 mV, 65 mV, and 130 mV to drive a current density of 10 mA cm −2 in 0.5 M H 2 SO 4 , 1.0 M KOH, and 1.0 M PBS , respectively, but also demonstrates high durability. It is worth to note that all these HER performances are on a par with commercial Pt/C catalysts for HER. This synthetic strategy provides possibility for the fabrication of carbon-based heterostructures with high catalytic activity and durability in harsh environments.
研究领域:
材料科学
·
能源化学
✓ 已验证
产品关联
DOI
高影响因子
Catalysis Science & Technology
·
2022
·Vol. 12
·期 7
·2257-2264
·
IF 6.177
Fei Zhang,Chunzheng Wu,Shuibo Wang,Shiwei Wang,Tong Li,Laixi Zou,Hongbo Yu,Hongfeng Yin
Although supported Rh nanoparticles (NPs) are one of the best catalysts for the selective hydrogenation of phenol to cyclohexanol, they still suffer from poor selectivity problems. In this study, we promoted the selectivity of Rh NPs with CoOx through an in situ transformation of the bimetallic RhCo NPs on SiO2. Among the obtained Rh–CoOx/SiO2 catalysts, the one with a Co/Rh molar ratio of 1/3 exhibited the highest phenol conversion (i.e., 98.1%) and the highest selectivity to cyclohexanol (i.e., 99.4%). Our study showed that CoOx promoters modified the electronic states of Rh and created new active sites at their interface, which are beneficial to the activation of phenol and the desorption of cyclohexanol. Excessive coverage of Rh by CoOx, however, would cause deactivation due to the less exposure of the Rh–CoOx interface.
研究领域:
催化
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化学工程
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF CATALYSIS
·
2018
·
IF 6.759
Zhou Ren,Yang Liu,Yuan Lyu,Xiangen Song,Changyong Zheng,Siquan Feng,Zheng Jiang,Yunjie Ding
A novel Rh based porous composed N polymer with hierarchical pore, high surface area and high thermal stability (Rh-POL-2BPY) was successfully obtained by impregnation of Rh 2 (CO) 4 Cl 2 solution of dichloromethane. And based on Rh species as the most active carbonylation site, Rh-POL-2BPY was selected as a catalyst applied in heterogeneous methanol carbonylation system and behaved excellent carbonylation activity (TOF ≈ 1400 h −1 ) under 195 °C, 2.5 MPa, higher than the corresponding homogeneous system without acetic acid. In addition, contrast to the most reported unstable heterogeneous methanol carbonylation systems, Rh-POL-2BPY could maintain incredibly outstanding stability for near 400 h owing to the firm coordination bond between Rh and N and high exposed N content in the polymer. Here, POL-2BPY apart from its heat-resisting property acts as massive rivets to immobilize the Rh species in its framework solidly during carbonylation process. XPS, XANES, HAADF-STEM and EXAFS results verify the N species of bipyridine, the single atom dispersion of Rh and Rh N coordination bond. And above all, the novel five-coordinated Rh center is proposed as the real active site of methanol carbonylation by EXAFS spectra.
研究领域:
化学工程
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材料科学
·
催化化学
✓ 已验证
产品关联
DOI
高影响因子
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
·
2022
·
IF 7.139
Y.F. Wang,X. Luo,W.J. Lu,L. Yang,B. Huang,P.T. Li,Y.Q. Yang
Pt group metals display lower HER activity in alkaline solution than in acidic solution, because they are inefficient in the water dissociation step (Volmer step). Compared with Pt, the activity difference of Rh in alkaline and acidic media is much smaller. Meanwhile, Ni(OH) 2 is proved to be an effective catalyst for water dissociation. Therefore, Rh–Ni(OH) 2 /C nanocomposites with different Rh:Ni(OH) 2 ratios were synthesized by a co-deposition/partial reduction method, and their microstructures as well as electrocatalytic properties were studied. The results show that Rh and Ni(OH) 2 display synergistic effect in Rh–Ni(OH) 2 /C nanocomposites. The Rh–Ni(OH) 2 /C nanocomposite with a molar ratio of Rh to Ni(OH) 2 of 1:1 exhibits the highest activity. It shows an overpotential of 36 mV at 10 mA cm −2 and a Tafel slope of 32 mV dec −1 for HER in alkaline media , which is superior to commercial Pt/C. In addition, the Rh–Ni(OH) 2 /C (1:1) nanocomposite shows excellent durability in alkaline media as well.
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
APPLIED ORGANOMETALLIC CHEMISTRY
·
2020
·Vol. 35
·期 2
·e6104
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IF 3.14
Kuan Wang,Jie Lan,Zhen-Hong He,Zhe Cao,Weitao Wang,Yang Yang,Zhao-Tie Liu
The synthesis of benzyl alcohols (BAs) is highly vital for their wide applications in organic synthesis and pharmaceuticals. Herein, BAs was efficiently synthesized via hydroxymethylation of phenylboronic acids (PBAs) and paraformaldehyde over a simple Rh PPh 3 catalyst combined with an inorganic base (NaOH). A variety of BAs with the groups of CH 3 − , CH 3 O − , Cl − , Br − , and so on were obtained with moderate to good yields, indicating that the protocol had a good universality. Density functional theory (DFT) calculations proposed the Hayashi-type arylation mechanism involved the arylation step of PBA and Rh(OH)(PPh 3 ) 2 catalyst to form Rh(I)-bound aryl intermediates and the hydrolysis step of Rh(I)-bound aryl intermediates and HCHO to generate BA product (the rate-determining step). The present route provides a valuable and direct method for the synthesis of BAs and expands the application range of paraformaldehyde.
研究领域:
有机化学
·
理论化学
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2023
·
IF 15.1
Guangjun Ji,Cunyao Li,Pan Gao,Miao Jiang,Lei Ma,Guoqing Wang,Guangjin Hou,Li Yan,Yunjie Ding
Tuning the microenvironment surrounding single atom metals is an effective but challenging way to regulate the performance of single atom catalysts (SACs). Herein, we prepared a series of P, N-abundant porous organic polymers (P&N-POPs) with diverse framework flexibility and coordination ability to serve as SACs’ carriers. The microenvironment (coordination site, coordination number) surrounding Rh and the equilibrium of ea / ee -HRh(CO) 2 P 2 active species were effectively regulated in Rh/P&N-POPs catalysts. Our study shows that the specific active ee -HRh(CO) 2 (P) 2 species confined in the flexible polymeric skeleton endowed the Rh/ m PPh 3 &PPD-POP with superior activity (TOF = 2000 h −1 ), selectivity of aldehydes (93.5 %), ratio of linear aldehyde to branched aldehyde (l/b ratio = 15.9), favorable stability (10 recycling runs without activity loss) and extensive substrate applicability (19 kinds of olefins) in hydroformylation reactions. Multiple characterization techniques (EXAFS, STEM, in-situ FTIR etc.) were employed to get insights into this effective strategy to regulate the performance of single atom catalysts (SACs).
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
GREEN CHEMISTRY
·
2016
·Vol. 18
·期 10
·2995-3005
·
IF 8.506
Cunyao Li,Li Yan,Lanlu Lu,Kai Xiong,Wenlong Wang,Miao Jiang,Jia Liu,Xiangen Song,Zhuangping Zhan,Zheng Jiang,Yunjie Ding
A vinyl functionalized biphephos ligand with high steric hindrance was copolymerized with tris(4-vinphenyl)phosphane and other ligands to afford efficient porous organic copolymers (POPs) through the solvothermal synthesis technique. By employing the copolymer self-supported heterogeneous Rh/CPOL-bp&P catalysts, the hydroformylation of propene to linear-butaldehyde can be performed efficiently in a continuous fixed-bed reactor with high regioselectivity (l/b > 24), activity (TOF > 1200 h−1) and stability (over 1000 h) under mild conditions (70 °C, 0.5 MPa), which represents a substantial improvement in the efficiency of this important industrial process. EXAFS and HAADF-STEM showed that the Rh was a single atom dispersion, which explained well the high efficiency of the Rh/CPOL-bp&P catalysts. Compared with liquid–liquid biphasic (LLB) and ionic liquid (IL) systems, this highly efficient solvent free system has the advantages of simple operability, and almost no waste emission, which meets the demands of green industrial processing.
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
JOURNAL OF MOLECULAR CATALYSIS A-CHEMICAL
·
2014
·
IF 3.679
Sheng-Jie Chen,Yong-Qi Li,Yong-Yong Wang,Xiao-Li Zhao,Ye Liu
The ionic hybrid P,N-ligands of 1 and 2 have been synthesized as one type of unconventional tertiary phosphines with the advantages of both the π-accepting ligands and the hemilabile ligands. The corresponding ionic Rh(I)-complexes of 1A and 2A proved to be more efficient catalysts for hydroformylation of 1-octene over isomerization than the traditional Rh I (acac)(CO)(PPh 3 ), due to the π-backdonation interaction in Rh → P linkage and the hemilabile ligation of N,P-coordinating sites to Rh-center. The in situ high-pressure FT-IR analysis indicated that: (1) the formation and lifetime of the active Rh H species (2047 cm −1 ) derived from 1A are facilitated by the presence of ligand 1 ; (2) the formation of the active Rh H species is depressed without the aid of the P,N-hemilabile ligation; and (3) the active Rh H species derived from Rh I (acac)(CO)(PPh 3 ) is unstable and susceptible to the formation of the inactive carbonyl-bridged Rh-dimer.
研究领域:
化学
·
催化反应
✓ 已验证
DOI
高影响因子
RSC Advances
·
2020
·Vol. 10
·期 57
·34381-34386
·
IF 3.119
Lele Chen,Jinghao Tian,Huaxing Song,Zhaohua Gao,Haisheng Wei,Wenhua Wang,Wanzhong Ren
Hydroformylation of olefins is one of the most important industrial processes for aldehyde production. Therein, the leaching of active metals for heterogeneous catalysts is an important issue in the hydroformylation reaction, particularly for higher olefins to produce higher alcohols. Here, different Rh/ZnO catalysts with diverse ZnO as a support were investigated and a home-made ZnO50 support was selected to prepare the Rh/ZnO50@ZIF-8 core–shell structure catalyst, which was synthesized by the growth of ZIF-8 with ZnO50 as the sacrificed template to afford Zn source. Compared with the Rh/ZnO50 catalyst, the Rh/ZnO50@ZIF-8 catalyst demonstrated a better cyclic stability in the hydroformylation of 1-dodecene. Combining the experiment and characterization results, it was concluded that the ZIF-8 shell on the Rh/ZnO50 catalyst effectively prevented the leaching of metal Rh into the reaction solution. Moreover, the Rh/ZnO50@ZIF-8 catalyst exhibited good universality for other higher olefins. This work provides a useful guideline for immobilizing the active species in heterogeneous catalysts for the hydroformylation reaction.
研究领域:
催化
·
化学工程
·
材料科学
✓ 已验证
DOI
PubMed
高影响因子
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