CHEMICAL ENGINEERING JOURNAL
·
2021
·
IF 13.273
Ming Lei,Yao Tang,Huimin Wang,Lihua Zhu,Guihua Zhang,Yu Zhou,Heqing Tang
It is still very difficult to achieve rapid cleavage of C-Cl bond of highly-chlorinated benzenes by catalytic reduction process under mild conditions. By using pentachlorobenzene (PentaCB) as a representative of highly-chlorinated benzenes, we proposed a strategy to achieve rapid and complete dechlorination of highly-chlorinated benzenes by exploiting palladium with low content deposited g-C 3 N 4 (Pd/g-C 3 N 4 ) as a catalyst with NaBH 4 as a reductant. Under favorable conditions, this strategy yielded a dechlorination efficiency of 100% for PentaCB (0.4 mmol L −1 ) in methanol solution at 30 °C within 20 min, and especially the consumption of NaBH 4 is as low as 10 mmol L −1 with a molar ratio of Cl atoms to NaBH 4 of only 1:5. A hydro-dechlorination pathway was confirmed to dominate the dechlorination of PentaCB, which involves active hydrogen species (H*) as being identified by electron spin resonance (ESR) monitoring and isotope labelling experiments. The dechlorination rate constant value of chlorobenzenes (CBs) was only a little dependent on the number of chlorine atoms and the chlorine atom with smaller steric hindrance was prior to be substituted by H*. A catalytic mechanism that Pd nanoparticles played an important role on both the weakening/breaking of C-Cl bond and the formation of active hydrogen species was further clarified: Pd exerts affinity interaction on chlorine atoms at ortho -position of CBs molecules to form adsorbed state [CBs] ads ; H* was formed on the Pd surface due to its strong ability in H* retainment; subsequently the generated H* attacks the C-Cl bond in [CBs] ads to achieve hydrodechlorination. The new method provides a highly efficient method to remove halogenated pollutants.
研究领域:
环境科学
·
催化化学
✓ 已验证
DOI
高影响因子
ChemCatChem
·
2024
·
IF 3.8
Jinlian Liu,Liang Jiang,Bo Xing,Fuping Zhang,Yi Wang,Qilong Zhao,Mingliang Wu,Xin Chen,Guo Yang
Graphical The Pd/ZrO 2 catalyst prepared by the impregnation reduction method showed excellent activity and selectivity in the synthesis of HMTHF via the selective hydrogenation of the furan ring in 5-HMF at ambient hydrogen pressure and room temperature. Furthermore, the influence of the type of active hydrogen species on the hydrogenation of furan rings was proved by hydrogen spillover experiments. 5-Hydroxymethylfurfural (5-HMF) derived from lignocellulose represents an important platform molecule that could be employed in the selective hydrogenation of the furan ring to prepare 5‑hydroxymethyltetrahydrofurfural (HMTHF). However, the reported catalytic systems for the synthesis of HMTHF using 5-HMF still require additional hydrogen pressure. In this study, the Pd/ZrO 2 catalyst with uniformly dispersed Pd nanoparticles was prepared via a simple impregnation reduction process. This catalyst exhibited excellent catalytic activity and selectivity for the hydrogenation of 5-HMF to HMTHF. High HMTHF yields up to 92.3% were produced under mild reaction conditions of ambient hydrogen pressure and room temperature in methanol solvent. This result was superior to the most catalytic systems that had been reported so far. The mechanism study revealed that the active hydrogen species on the surface of the Pd nanoparticles and the reaction solvent in this study were the pivotal factors influencing the hydrogenation of furan rings in 5-HMF.
研究领域:
化学工程
·
催化科学
✓ 已验证
产品关联
DOI
高影响因子
ACS Applied Energy Materials
·
2024
·
IF 5.4
Heng Chen,Li Li,Shichao Zhang,Chaofeng Zhang
Recently, as an important product of the CO2 hydrogenation reaction and a crucial hydrogen storage material, the transformation of formic acid (FA)/formate to H2 or active hydrogen species has attracted much attention. However, obtaining a robust and efficient solid catalyst constitutes a major challenge. In this work, nitrobenzene was used as the active hydrogen species capture agent, and various Pd-based catalysts were prepared and used to refine the influence factors of FA decomposition over TiO2-supported palladium catalysts. The catalysts’ deactivation and regeneration process, control reactions, and catalyst characterizations indicate that the electrical state of the Pd species and interface microsurroundings played decisive roles in the activity and reusability of PdO/TiO2. Based on the results obtained, a tentative mechanism with the active sites (Pdδ+–O–Ti) located at the PdO/TiO2 interface was proposed, which would be useful for the chemistry of the Pd catalyst and formate decomposition.
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
ACS Catalysis
·
2024
·
IF 11.3
Minghua Dong,Sen Luan,Yuxuan Wu,Bin Zhang,Ye Liu,Huizhen Liu,Buxing Han
Unveiling the mechanism behind catalyst-dependent solvent effects for hydrogenation reactions is critically important yet presents significant challenges. In this work, focusing on furfural hydrogenation over Pd-based catalysts, we observe that distinct active hydrogen species present on Pd/MgO and Pd/TiO2 exhibit different responses to solvation environments, consequently influencing the selectivity in diverse solvents. Product distribution over Pd/MgO remains unaffected by the solvents used that tetrahydrofurfural (THFAL) emerged as the primary product in both organic solvents and water. Conversely, product distribution over Pd/TiO2 highly depends on the solvents; THFAL dominates in organic solvents, whereas furfural alcohol (FOL) becomes the primary product in water. The disparate selectivity upon alteration of supports and solvents is demonstrated by neural network-enhanced molecular dynamics simulations and microkinetic modeling. The active hydrogen species on the support are stabilized in water by water-mediated charge reconstructions, facilitating the hydrogenation of C═O to produce FOL. A spillover pathway where hydrogen species transfer to supports directly without involving hydrogen bond networks is dynamically preferred in both water and organic solvents.
研究领域:
催化化学
·
理论计算化学
✓ 已验证
DOI
高影响因子
WATER RESEARCH
·
2025
·
IF 12.4
Hao Zhang,Xupeng Liu,Biao Zhou,Ziyue Chen,Jundi Cheng,Kehang Zeng,Lizhi Zhang,Hongwei Sun,Zhihui Ai
Mercury (Hg) is a toxic metal of great concern, and its reduction from Hg(II) to Hg(0) is crucial to prevent its mobilization and transformation to even more hazardous methylmercury. Fe° could reduce Hg(II), but the role of active hydrogen species (*H) remains unexplored. Herein, we prepared the phosphate-modified zero-valent iron by ball milling (P-ZVI bm ) and investigated its Hg(II) reduction and immobilization capacity compared with the ZVI bm counterpart. P-ZVI bm rapidly adsorbed and reduced Hg(II) from water at a rate 22 times faster than ZVI bm , with *H accounting for 36% of Hg(II) reduction. A greatly higher proportion of negative surface electrostatic potential on P-ZVI bm (50.38%) than ZVI bm (37.61%) facilitated the adsorption of Hg(II) cation. H 2 O adsorption on P-ZVI bm was more favorable, as demonstrated by the in situ ATR-FTIR spectra, H 2 O TPD-mass spectra, and the substantially lower adsorption energy (-0.78 eV) than ZVI bm (-0.17 eV). The energy span of H 2 O dissociation to *H also decreased from 2.80 eV on ZVI bm to 1.99 eV on P-ZVI bm . Moreover, *H adsorption energy on P-ZVI bm (1.70 eV) was lower than on ZVI bm (-1.20 eV), thereby inhibiting consumption of *H by H 2 evolution. P-ZVI bm demonstrated remarkable efficacy in removing Hg(II), Cu(II), Ni(II), Cd(II), and Pb(II) from electroplating and mining wastewater. These results highlight P-ZVI bm as a promising material for Hg(II) and other heavy metal remediation and underscore the essential role of *H in the enhanced Hg(II) reduction.
研究领域:
环境科学
·
材料科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
LANGMUIR
·
2022
·
IF 4.331
Zhenyu Zhao,Xuting Wang,Shifu Wang,Zuoyi Xiao,Shangru Zhai,Jiliang Ma,Xiaoli Dong,Haodong Sun,Qingda An
The development of g-C3N4-based photocatalysts with abundant active sites is of great significance for photocatalytic reactions. Herein, a smart and robust strategy was presented to fabricate three-dimensional (3D) g-C3N4 nanosheet-coated alginate-based hierarchical porous carbon (g-C3N4@HPC), including coating melamine on calcium alginate (CA) hydrogel beads, freeze-drying hydrogel beads as well as pyrolysis at high temperatures. The resulting photocatalyst possessed a significantly high surface area and a large amount of interconnected macropores compared with porous carbon without the melamine coating. The unique structural features could effectively inhibit the curling and agglomeration of g-C3N4 nanosheets, provide abundant photocatalytic active sites, and promote mass diffusion. Therefore, the g-C3N4@HPC composite exhibited remarkable photocatalytic activity and outstanding stability toward the photoreduction of 4-nitrophenol (4-NP) to 4-aminophenol (4-AP) by NaBH4 under natural sunlight and simulated visible-light irradiation (λ > 420 nm) using a 300 W xenon lamp. Moreover, the mechanism toward the photocatalytic reaction was extensively studied by quenching experiments and electron spin resonance (ESR) experiments. The results showed that active hydrogen species were able to be achieved by following a dual-channel pathway in the NaBH4 system, which included photocatalytic reduction of H+ ions and photocatalytic oxidation of BH4– ions. This work not only opens up a new way to design efficient photocatalysts for various reactions but also provides a reference for an in-depth study of the photoreduction mechanism.
研究领域:
材料科学
·
环境科学
✓ 已验证
DOI
PubMed
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
·
2021
·
IF 7.312
Jia Deng,Xiang Zhan,Feng Wu,Shuxian Gao,Li-Zhi Huang
Trichloroethylene (TCE), one of the most frequently detected chlorinated organic pollutants (COPs) in groundwater, has potential risks to human health. The bimetallic system consisting of zero-valent iron (ZVI) and a second catalytic metal has been widely investigated for reductive dechlorination of COPs. However, the passivation layer of ZVI inhibits the electron transfer causing a low dechlorination efficiency. In this work, we designed a novel bimetallic system using Fe(OH) 2 and Ni for fast dechlorination of TCE. The reduction efficiency of TCE reaches 94.8 % after 5 h of reaction in the Fe(OH) 2 /Ni system. TCE was completely dechlorinated to nontoxic gas products including ethylene and ethane, which was attributed to the generation of active hydrogen species (H*) in the system. The Ni 2+ cations undergo the process of hydroxylation and olation. Subsequently, electrons of Fe(OH) 2 were transferred to Ni(II) causing the formation of Ni(0). The catalytic Ni(0) sites generate H* for TCE dechlorination via catalytic reduction of H 2 O/H + . A part of Fe(II) in the Fe hydroxide layer of Fe(OH) 2 was oxidized to Fe(III) leading to the formation of green rust with a hexagonal structure. Our work demonstrates Fe(OH) 2 /Ni is a promising composite material for the remediation of TCE-contaminated groundwater.
研究领域:
环境科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
ENVIRONMENTAL SCIENCE & TECHNOLOGY
·
2018
·
IF 6.653
Ming Lei,Shun Guo,Zhiying Wang,Lihua Zhu,Heqing Tang
Fast and deep debromination of polybrominated diphenyl ethers (PBDEs) under mild conditions is a challenge in the field of pollution control. A strategy was developed to achieve it by exploiting Cu/TiO2 composites as a noble-metal-free catalyst. Toward the debromination of 2,2′,4,4′-tetrabromodiphenyl ether (BDE47) as a typical PBDE, the use of Cu/TiO2 as a catalyst and hydrazine hydrate (N2H4·H2O) as a reducing agent yielded a degradation removal of 100% and a debromination efficiency of 87.7% in 3 s. A complete debromination of BDE47 at 1500 mg L–1 was possible by successively adding N2H4·H2O. A debromination pathway involving active H atom species was proposed for the catalytic transfer hydrogenation (CTH) of PBDEs according to the identified degradation intermediates. A mechanism was further clarified by density functional theory calculations: electrons are delivered from N2H4·H2O to the metallic Cu atom via a coordination of N in N2H4·H2O with Cu atoms. The electron-trapped Cu atom interacts with adsorbed BDE47 to form a transition complex, and then the debromination of this complex occurs on the surface of Cu nanoparticles due to the hydrogen donation of N2H4·H2O through the CTH process. The new method provides a highly efficient method to remove brominated pollutants.
研究领域:
环境科学
·
污染控制化学
·
材料科学
✓ 已验证
DOI
高影响因子
Nature Communications
·
2022
·Vol. 13
·期 1
·1-12
·
IF 17.694
Yang Ganceng,Jiao Yanqing,Yan Haijing,Xie Ying,Tian Chungui,Wu Aiping,Wang Yu,Fu Honggang
Paired electroreduction and electrooxidation of organics with water as a feedstock to produce value-added chemicals is meaningful. A comprehensive understanding of reaction mechanism is critical for the catalyst design and relative area development. Here, we have systematically studied the mechanism of the paired electroreduction and electrooxidation of organics on Fe-Mo-based phosphide heterojunctions. It is shown that active H* species for organic electroreduction originate from water. As for organic electrooxidation, among various oxygen species (OH*, OOH*, and O*), OH* free radicals derived from the first step of water dissociation are identified as active species. Furthermore, explicit reaction pathways and their paired advantages are proposed based on theoretical calculations. The paired electrolyzer powered by a solar cell shows a low voltage of 1.594 V at 100 mA cm −2 , faradaic efficiency of ≥99%, and remarkable cycle stability. This work provides a guide for sustainable synthesis of various value-added chemicals via paired electrocatalysis.
研究领域:
催化化学
·
电化学
·
材料科学
✓ 已验证
DOI
PubMed
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
·
2023
·
IF 8.6
Shubin Cheng,Qian Lei,Coner Deng,Weixin Lei,Honglin Chen
A green protocol for refining industrial chemicals containing formaldehyde (FA) impurities is presented here for the first time. FA, as an unreactant or a byproduct, causes separation problems in many industrial processes. It can be removed to a level of less than 1 ppm with easily separable methanol formation using commercial Cu/ZnO/Al 2 O 3 catalyst at atmospheric pressure in the absence of external hydrogen. The formation of methanol is achieved by the transfer of hydrogen species generated with the assistance of water to free FA, affording high methanol selectivity (62 %). By investigating potential intermediates and implementing deuterium labeling experiments, together with carbon and hydrogen balance calculations, a plausible pathway of water-assisted FA removal is proposed. Moreover, the in situ generated hydrogen species can be transferred directly into unsaturated compounds for selective reduction.
研究领域:
化学工程
·
催化
·
环境化学
✓ 已验证
产品关联
DOI
高影响因子
ACS ES&T Engineering
·
2025
·
IF 6.7
Hehe Qian,Tinghui Ma,Lili Shi,Shu Yan,Haisong Cui,Xueqing Luo,Fang Chen,Yuetan Su,Zhongbiao Wu,Xiaole Weng
Electrocatalytic hydrodechlorination (EHDC) is a promising strategy for remediating chlorinated organic pollutants by utilizing reactive hydrogen (H*) to cleave C–Cl bonds. Addressing the challenge of simultaneously optimizing H* generation and targeted pollutant adsorption/activation, this work introduces synergistic surface engineering of RuPd alloy nanocatalysts. Compositionally controlled RuPd nanoparticles (RuPd2, Ru2Pd3, and Ru2Pd) were synthesized via seed-mediated growth, yielding uniform sub-3.5 nm nanoparticles with homogeneous elemental distribution. The optimal RuPd2 electrocatalysts achieved 97.1% 2-chlorophenol conversion within 6 h at −0.85 V vs Ag/AgCl, exhibiting a mass activity of 28.3 min–1 g–1Pd, representing a 5.6-fold enhancement over monometallic Pd. Moreover, RuPd2 demonstrated enhanced durability, maintaining performance with less than 5% efficiency loss over 10 cycles. This enhanced EHDC performance originated from dual synergistic effects. Electron transfer from Ru to Pd facilitated H* generation kinetics, evidenced by a near-optimal ΔGH* (−0.25 eV) at Pd–Pd–Pd hollow sites, while Ru-rich surface domains significantly strengthened 2-chlorophenol adsorption and elongated the C–Cl bond to facilitate dechlorination. These spatially separated synergistic sites collectively achieve higher EHDC efficiency, establishing a unified catalyst design strategy that effectively orchestrates coupled surface processes, and provides a significant advance for efficient EHDC technology with broad environmental remediation implications.
研究领域:
环境催化
·
纳米材料化学
·
污染物降解
·
电化学
·
表面科学
·
能源与环境工程
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF COLLOID AND INTERFACE SCIENCE
·
2025
·
IF 9.7
Defu Yin,Lu Shen,Zewei Hu,Shitao Yu,Lu Li,Shiwei Liu,Yue Liu
The hydrogenation of phenolic compounds to achieve high value-added conversion is an important reaction in industrial applications. Promoting the hydrogenation process by regulating the properties of H active species has great potential. In this paper, we achieved in-situ metal doping using the one-pot hydrothermal strategy to regulate the cleavage pathway of H 2 on the surface of noble metals, thereby promoting the hydrogenation of phenol to form ketones. The results of catalytic performance, characterization and density functional theory (DFT) calculations confirmed that the Co doping regulated the surface properties of Pd metal, leading to easier heterolytic cleavage of H 2 to form electron-rich highly active H δ- species. Mechanistic studies showed that the modified metal surface was more favorable for the adsorption and activation of H 2 , and the electron-rich H δ- species could lower the hydrogenation barrier and promote the progress of the hydrogenation process. In addition, this strategy achieved the highly stable materials with core-shell via one-step synthesis, which showed good stability in continuous use. Our study presents a successful paradigm in biomass conversion, deepening the understanding of the regulation of hydrogenation processes.
研究领域:
催化化学
·
化学反应工程
·
材料科学
·
物理化学
·
工业化学
·
生物质转化
✓ 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）