MOLECULES
·
2025
·Vol. 30
·期 7
·1599
·
IF 4.6
Yang Li,Ying Wang,Longbo Zhang,Yanru Zhang,Jia Guo,Yanyan Wang,Chenglong Yu,Jun He,Zhenpeng Wang,Juanjuan Han,Qian Li,Tianbin Wu,Qingli Qian,Buxing Han
CO2is a greenhouse gas and a nontoxic, easily available and renewable C1feedstock. H2is a clean and cheap reductant that can be obtained from renewable energy. Olefins are platform chemicals that can be produced from a variety of raw materials such as petroleum, coal and renewable biomass. The production of carboxylic acids by combining olefins, CO2and H2is a sustainable and very promising protocol. However, only a few advances in this topic have been achieved because novel catalysts need to be developed. In this work, we demonstrate that a simple iridium-based catalyst could efficiently promote the synthesis of C2+carboxylic acids via the reaction of olefins with CO2and H2. The reaction was effectively accelerated by a simple iridium-based catalytic system at 170 °C, which may be applied to various olefin substrates. The catalytic mechanism was studied through a series of control experiments. The findings contribute to advancing the sustainable production of valuable products by the reaction of renewable CO2and green H2with platform chemicals.
研究领域:
化学催化
·
可持续化学
·
有机化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
·
2020
·
IF 3.573
Benyong Yang,Wentao Mu,Benedict Tsz Woon Lo,Sijie Liu,Zhihang Chen,Liam John France,Xuehui Li
NOx and CO formation is, at present, a consequence arising from fuel production, but their emission need not be. In this study, a series of novel Ir-containing TiO2-nanobelt catalysts were designed and prepared for the simultaneous removal of NOx and CO. Activity data demonstrates that the TiO2(B) support promotes NO reduction compared to anatase. Furthermore, reaction efficiency (RE), a measure of NOx consumption vis-à-vis that of CO, reveals that catalysts containing anatase promote CO oxidation more so than their TiO2(B) counterparts. Increasing Ir concentration over the latter promotes low-temperature catalytic performance, an effect believed to be linked to the formation of Ir0–IrO2 composites. In situ DRIFTS experiments reveal the relevance of nitrite/nitrate formation and consumption at 250 °C, a mechanism insinuated by the RE value. However, at 300 °C, both TOF and RE increase, signifying the participation of a faster and more-selective reaction, which appears consistent with the isocyanate-mediated pathway.
研究领域:
环境科学
·
催化化学
✓ 已验证
产品关联
DOI
高影响因子
ChemCatChem
·
2022
·Vol. 14
·期 6
·e202101794
·
IF 5.497
Longfei Zhu,Sen Ye,Jing Wang,Jiazheng Zhu,Guangke He,Xiang Liu
Graphical Hydrogen pool : Recyclable Ir/ZnO-catalysed additive-free transfer hydrogenation of aldehydes and ketones using methanol as hydrogen source was achieved at 110 °C, delivering alcohols in up to 98 % yield. The fine cooperation of ZnO and positively charged IrO x enables the complete cleavage of O−H and less reactive C−H bonds of methanol to generate active H for carbonyl hydrogenation. The use of methanol as abundant and low-toxic hydrogen source under mild and clean conditions is promising for the development of safe and sustainable reduction processes, but remains a daunting challenge. This work presents a recyclable ZnO-supported Ir catalyst for the additive-free transfer hydrogenation of aldehydes and ketones using methanol as hydrogen source at 110 °C, delivering alcohols in up to 98 % yield. Mechanistic studies disclose that methanol is first dehydrogenated to formaldehyde and then fully decomposed into active hydrogen species for hydrogenation. The superior performance is related to the high ratio of positively charged IrO x species and their ultrafine dispersion over ZnO. And the delicate cooperation of IrO x and ZnO enhances the catalytic activities for the selective scission of O−H and less reactive C−H bonds in methanol, maintaining a good balance between methanol decomposition and C=O hydrogenation in this green transfer hydrogenation.
研究领域:
化学催化
·
绿色化学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
Reaction Chemistry & Engineering
·
2022
·Vol. 8
·期 4
·778-783
·
IF 5.2
Huan Liu,Yi-Xuan Yao,Hong-Yan Shang,Da Yang,Yuan-Yu Tian
The tandem hydroformylation–acetalization of olefins with H2O as the hydrogen source was accomplished over an Ir(I)-catalyst using the phased warming strategy. Due to the release of protons by AlCl3-hydrolysis equilibrium, the tandem reaction was significantly enhanced. The conversion of 1-hexene was 100% and the selectivity for oxo-products was 89%, where 91% of acetals was obtained. Moreover, the hydrogenation by-products were detected to be less than 3%, showing that H2O as the hydrogen source inhibited the hydrogenation of olefins in this tandem reaction. Moreover, isotope-labeling experiments confirmed that water was the hydrogen source, and the key Ir–H active species for hydroformylation were captured by high-pressure 1H NMR spectroscopy analyses.
研究领域:
化学催化
·
有机合成
✓ 已验证
产品关联
DOI
高影响因子
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
·
2024
·
IF 8.1
Hao Wu,Guoxiang Wang,Xinxin Zhang,Qingwang Min,Jiacheng Wang,Dazhi Wang,Longsheng Cao
Water electrolysis is one of the most promising green hydrogen production technologies. However, using precious metal materials as electrodes for these electrolyzers incurs high costs. To address these challenges and simultaneously retain the catalytic activity of precious metals, we synthesize a low-iridium catalyst, Nd–IrO 2 . At 10 and -10 mA/cm 2 , this catalyst exhibits 233 and 36 mV overpotentials. Nd – IrO 2 maintains stability over prolonged operation in acidic environments, as evidenced by its consistent overpotential. Advanced calculations using density functional theory (DFT) have demonstrated that incorporating Nd and an ample amount of oxygen vacancies can modulate the d-band center of Ir and reduce the adsorption energy of electrochemical reaction intermediates. In summary, we present the synthesis of a low-iridium catalyst, which provides valuable insights for the design and development of catalysts with improved electrocatalytic performance.
研究领域:
材料科学
·
电化学
✓ 已验证
产品关联
DOI
高影响因子
ACS Catalysis
·
2021
·
IF 13.084
Chenyang Shen,Kaihang Sun,Zhitao Zhang,Ning Rui,Xinyu Jia,Donghai Mei,Chang-jun Liu
Iridium (Ir) catalysts have been extensively applied in homogeneous and photocatalytic CO2 conversion. However, CO2 hydrogenation to methanol over the supported Ir catalyst in a heterogeneous flowing reactor has not been reported yet. Here, we report that indium oxide supported Ir catalyst (Ir/In2O3) of high dispersion is very active for CO2 hydrogenation to methanol. Compared to In2O3, Ir/In2O3 shows a significantly higher activity with even higher methanol selectivity. For example, CO2 conversion of 17.7% is achieved on Ir/In2O3 of 10 wt % Ir loading with methanol selectivity over 70% and high methanol space time yield of 0.765 gMeOH h–1 gcat–1 at 4/1 of the CO2/H2 feed ratio, 21 000 h–1, 300 °C, and 5 MPa. With the catalysts tested, the higher Ir loading causes the higher activity. The catalyst characterization confirms an intense interaction between iridium and In2O3, which causes the high dispersion of the Ir catalyst with the Ir–In2O3 interface as the active site for selective hydrogenation of CO2 into methanol. The Ir loading not only enhances the formation of oxygen vacancies but also stabilizes the vacancies for improved CO2 activation. Further density functional theory studies reveal that the reverse water–gas shift route is more favorable over the formate route for CO2 hydrogenation to methanol over Ir/In2O3 catalyst.
研究领域:
催化化学
·
材料科学
·
理论计算
✓ 已验证
产品关联
DOI
高影响因子
ChemSusChem
·
2017
·Vol. 10
·期 16
·3268-3275
·
IF 7.226
Haili Tong,Yi Jiang,Qian Zhang,Jialing Li,Wenchao Jiang,Donghui Zhang,Na Li,Lixin Xia
Graphical A modified photoanode : An iridium complex is immobilized on a WO 3 electrode to construct a composite photoanode for photoelectrochemical (PEC) water splitting. The photoanode shows a significant improvement both in photocurrent and faradaic efficiency. Kinetic studies reveal that the molecular iridium catalyst exhibits a different interfacial charge-transfer mechanism on the WO 3 photoanode for PEC water oxidation compared to iridium oxide. The rational design of active photoanodes for photoelectrochemical (PEC) water splitting is crucial for future applications in sustainable energy conversion. A combination of catalysts with photoelectrodes is generally required to improve surface kinetics and suppress surface recombination. In this study, we present WO 3 photoanode modified with the iridium complex [(H 4 dphbpy)Ir III (Cp*)Cl]Cl (Ir-PO 3 H 2 ; H 4 dphbpy=2,2′-bipyridine-4,4′-bisphosphonic acid, Cp*=pentamethylcyclopentadiene (WO 3 +Ir-PO 3 H 2 )- for PEC water oxidation. When Ir-PO 3 H 2 is anchored to a WO 3 electrode, the photoanode shows a significant improvement in both photocurrent and faradaic efficiency compared to the bare WO 3 photoanode. Under simulated sunlight illumination (AM 1.5G, 100 mW cm −2 ) with an applied bias of 1.23 V (vs. reversible hydrogen electrode), the photoanode exhibits a photocurrent of 1.16 mA cm −2 in acidic conditions, which is double that of the bare WO 3 photoanode. The faradaic efficiency is promoted from 56 % to 95 %. Kinetic studies reveal that Ir-PO 3 H 2 exhibits a different interfacial charge-transfer mechanism on the WO 3 photoanode for PEC water oxidation compared to iridium oxide. Ir-PO 3 H 2 , as a water-oxidation catalyst, can accelerate the surface charge transfer through rapid surface kinetics.
研究领域:
材料科学
·
催化化学
·
能源转换技术
✓ 已验证
DOI
PubMed
高影响因子
CHINESE CHEMICAL LETTERS
·
2019
·
IF 3.839
Xiao-Yong Zhai,Xiao-Qing Wang,Yi-Xuan Ding,Yong-Gui Zhou
Partially biobased polysilylethers (PSEs) are synthesized via dehydrocoupling polymerization catalyzed by an anionic iridium complex. Different types (AB type or AA and BB type) of monomers are suitable. Levulinic acid (LA) and succinic acid (SA) have been ranked within the top 10 chemicals derived from biomass. BB type monomers (diols) derived from LA and SA have been applied to the synthesis of PSEs. The polymerization reactions employ an air-stable anionic iridium complex bearing a functional bipyridonate ligand as catalyst. Moderate to high yields of polymers with number-average molecular weights ( M n ) up to 4.38 × 10 4 were obtained. A possible catalytic cycle via an Ir-H species is presented. Based on the results of kinetic experiments, apparent activation energy of polymerization in the temperature range of 0–10 °C is about 38.6 kJ/mol. The PSEs synthesized from AA and BB type monomers possess good thermal stability ( T 5 = 418 °C to 437 °C) and low glass-transition temperature ( T g = −49.6 °C).
研究领域:
材料科学
·
催化化学
✓ 已验证
DOI
高影响因子
Journal of Energy Chemistry
·
2014
·
IF 0
Min Jiang,Dandan Zhu,Xuebo Zhao
Electrolysis of ammonia in alkaline electrolyte solution was applied for the production of hydrogen. Both Pt-loaded Ni foam and Pt-Ir loaded Ni foam electrodes were prepared by electrodeposition and served as anode and cathode in ammonia electrolytic cell , respectively. The electrochemical behaviors of ammonia in KOH solution were individually investigated via cyclic voltammetry on three electrodes, i.e. bare Ni foam electrode, Pt-loaded Ni foam electrode and Pt-Ir loaded Ni foam electrode. The morphology and composition of the prepared Ni foam electrode were analyzed by scanning electron microscopy (SEM) and X-ray diffraction (XRD). Effects of the concentration of electrolyte solution and temperature of electrolytic cell on the electrolysis reaction were examined in order to enhance the efficiency of ammonia electrolysis. The competition of ammonia electrolysis and water electrolysis in the same alkaline solution was firstly proposed to explain the changes of cell voltage with the electrolysis proceeding. At varying current densities, different cell voltages could be obtained from galvanostatic curves. The low cell voltage of 0.58 V, which is less than the practical electrolysis voltage of water (1.6 V), can be obtained at a current density of 2.5 mA/cm 2 . Based on some experimental parameters, such as the applied current, the resulting cell voltage and output of hydrogen gas , the power consumption per gram of H 2 produced can be estimated.
研究领域:
能源科学
·
催化化学
✓ 已验证
产品关联
DOI
BIORESOURCE TECHNOLOGY
·
2021
·
IF 9.642
Song Li,Lele Jin,Haiyong Wang,Xiangqian Wei,Wenzhi Li,Qiying Liu,Xinghua Zhang,Lungang Chen,Longlong Ma,Qi Zhang
Herein, WO x –decorated Ir/SiO 2 (W/Ir = 0.06) and HZSM-5 were coupled to selectively convert microcrystalline cellulose (MCC) into C 6 alkanes. A 92.8% yield of liquid alkanes including an 85.3% yield of C 6 alkanes was produced at 210 °C. Cellulose hydrolysis, glucose hydrogenation and sorbitol hydrodeoxygenation were integrated to produce alkanes via a sorbitol route. Ir-WO x /SiO 2 showed high performance for hydrogenation and hydrodeoxygenation reactions after hydrolysis catalyzed by HZSM-5. The intimate contact between WO x and Ir enhanced the synergistic interaction through the electron transfer from Ir to WO x . The interaction strengthened the reduction capability of Ir for hydrogenations, as well as improved the adsorption and activation of C-O bonds on reduced WO x for deoxygenations. The monotungstate WO x species provided moderate Lewis acids to cooperate with Ir to accelerate hydrodeoxygenations with alleviated retro -aldol condensation to yield more C 6 alkanes.
研究领域:
化学工程
·
催化科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Nanoscale
·
2019
·Vol. 11
·期 48
·23206-23216
·
IF 6.97
Tao Yang,Yihui Wang,Wenxian Wei,Xinran Ding,Maoshuai He,Tingting Yu,Hong Zhao,Dongen Zhang
Fuel cells are expected to be one of the most promising alternatives to the increasingly scarce fossil fuels, and Pt is the most commonly used catalyst for anodic and cathodic electrochemical reactions. To realize large-scale commercialization, it is most urgent to improve the efficiency of Pt and reduce the cost. Here, we synthesized an octahedral Pt–Ni–Ir yolk–shell catalyst through stepwise co-deposition (SCD), surface-limited Pt deposition (SLPD) and Ni-coordinating etching (NCE) processes. Experimental studies showed that the catalytic activities of the as-prepared trimetal yolk–shell catalyst were several times higher than that of the commercial Pt/C towards oxygen reduction and methanol oxidization under both acidic and alkaline conditions. This work may be extended to designing other multimetallic functional materials with complex hierarchical nanostructures, which is conducive to greatly enhancing the performance.
研究领域:
材料科学
·
电化学
·
催化作用
✓ 已验证
DOI
PubMed
高影响因子
Nature Nanotechnology
·
2025
·
IF 34.9
Teng Zhenyuan,Zhang Zhenzong,Tu Ying,Zhang Qitao,Jian Nan,Yang Liujun,Xiao Jiadong,Ding Jie,Huang Longzhen,Teruhsia Ohno,Wang Chengyin,Zhang Dengsong,Yu Han,Lu Jianmei,Su Chenliang,Liu Bin
Selective asymmetric oxidation of glycerol (GLY) to hydroxypyruvic acid (HPA) offers an attractive approach for chiral drug synthesis, but this process is highly challenging. Here we develop a photocatalytic method to achieve heterogeneous selective photooxidation of GLY to HPA over rubidium (Rb) and iridium (Ir) catalytic pairs decorated on a poly(heptazine imide) framework. The Rb sites effectively adsorb GLY molecules through the terminal –OH groups, thus inhibiting their oxidation during photoreaction, while the Ir sites enhance the oxygen reduction reaction and the in situ generated surficial oxygen-reduction radicals on Ir can protect the reactive C-centred radical intermediates produced during photooxidation. The spatial arrangement of Rb and Ir sites facilitates hydrogen extraction—an essential rate-determining step for GLY photooxidation—and protects C3 radical intermediates from overoxidation. This photocatalytic system achieves a remarkable productivity for HPA synthesis (~8,000 μmol of HPA per gram of photocatalyst per hour) under visible-light illumination.
研究领域:
化学工程
·
材料科学
·
光催化
✓ 已验证
产品关联
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）