MATERIALS CHEMISTRY AND PHYSICS
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2025
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IF 4.7
Qingfang Jiang,Wujian Zhang,Weijian Ge,Yiping Jin,Wenfeng Han,Ying Li,Haodong Tang
Sintering deactivation of loaded precious metal catalysts is a pressing issue in the field, significantly reducing catalyst activity. Among them, the redispersion of carbon-loaded precious metal catalysts under a high-temperature atmosphere suffers from the problem of carbon carriers being prone to carbonization. In this study, the sintered PdZn/AC catalysts could be redispersed at low temperatures by adding the additive Zn. Combined with TEM, XRD, XPS, and other characterization means, it was found that the main reason for the redispersion of the sintered catalysts was that the Zn additive could form an alloy with Pd, which promoted the formation of high-valent Pd species, which exfoliated into small particles by oxidation in the O 2 –CO atmosphere. In addition, the factors that influenced the process (Zn content, redispersion temperature, treatment time, and number of treatments) were investigated using the controlled variable method. The present work presents a new idea for recycling sintered precious metal catalysts.
研究领域:
催化化学
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材料科学
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化学工程
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表面化学
✓ 已验证
产品关联
DOI
高影响因子
Sustainable Energy & Fuels
·
2018
·Vol. 2
·期 6
·1206-1215
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IF 0
Fanglin Li,Jianchun Jiang,Peng Liu,Qiaolong Zhai,Fei Wang,Chung-yun Hse,Junming Xu
Molecular structure transformation is a critical step for synthesis of aviation biofuels from triglycerides, to yield alkanes, aromatics and cycloalkanes. To this end, triglycerides were treated by catalytic cracking coupled with rectification to obtain hydrocarbon fuels, and the molecular weight of the liquid product was adjusted to the desirable boiling range of aviation fuel. To further modify the molecular structures, the pyrolytic hydrocarbons were partially converted into aromatics and cycloalkanes by a two-step process. Different raw materials including soybean oil, rubber seed oil, waste cooking oil and acidified oil were cracked with a 5 wt% base catalyst at 350–450 °C (under the atmospheric pressure) in a benchtop reactor. Afterwards, the linear hydrocarbons of C8–C15 size were transformed into aromatics by HZSM-5 at 350 °C for 6 h. Then, a portion of the aromatics were converted into cycloalkanes catalyzed by Pd/AC at 200 °C and 6 MPa (H2) for 6 h. As a result, a desirable mixture of linear hydrocarbons, aromatics and cycloalkanes was obtained with a similar composition and properties to traditional fossil aviation fuels.
研究领域:
生物化学
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能源科学
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催化化学
✓ 已验证
产品关联
DOI
CHINESE JOURNAL OF CHEMICAL ENGINEERING
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2021
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IF 3.171
Chunhua Zhang,Zhengyan Qu,Hong Jiang,Rizhi Chen,Weihong Xing
Phenol hydrogenation is a green route to prepare cyclohexanone, an intermediate for the production of nylon 66 and nylon 6. The development of high-performance catalysts still keeps a great challenge. Herein, the activated carbon (AC) was modified with an acidic material Nb 2 O 5 to adjust the microstructure and surface properties of AC, and the influences of the calcination temperature and Nb 2 O 5 content on the catalytic performance of the Pd/AC-Nb 2 O 5 catalysts for the phenol hydrogenation to cyclohexanone were investigated. The Nb 2 O 5 with proper content can be highly uniformly distributed on the AC surface, enhancing the acidity of the Pd/AC-Nb 2 O 5 catalysts with comparable specific surface area and Pd dispersion, thereby improving the catalytic activity. The hybrid Pd/AC-10Nb 2 O 5 -500 catalyst exhibits the synergistic effect between the Pd nanoparticles and AC-10Nb 2 O 5 , which enhances the catalytic activity for the hydrogenation of phenol. Furthermore, the as-prepared Pd/AC-10Nb 2 O 5 -500 catalyst shows good reusability during 7 reaction cycles.
研究领域:
化学工程
·
催化材料
✓ 已验证
DOI
高影响因子
ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH
·
2021
·Vol. 28
·期 47
·67098-67107
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IF 4.223
Long Yingtao,Liang Jianjun,Xue Yinghao
A novel composite (nZVI/Pd-AC) was prepared by loading nanoscale zero-valent iron (nZVI) and Pd on activated carbon (AC) electrode under electrodeposition with ultrasound, which was used to reductive degradation of methylene blue (MB). The loading contents of Fe and Pd in composite materials were 15.84% and 2.06%, respectively. XPS results further confirmed that the as-prepared material contained Fe 0 and Pd 0 . Without external conditions, MB could be degraded in the presence of nZVI/Pd-AC and reached equilibrium within 180 min. To investigate the reusability, the re-electrodeposition strategy was effective to refresh the active sites of nZVI/Pd-AC, and the removal efficiency only reduced by 4.51% in five circles indicating the good reusability of nZVI/Pd-AC composites. GC–MS was used to identify possible degradation pathways of MB; the results showed that the degradation products were mainly N, N-dimethylaniline and 2-amino-5-dimethylamino-benzenesulfonic acid. And the S–C, C–N bonds are the sites easier to be attacked. Graphical abstract
研究领域:
环境科学
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材料科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
FUEL PROCESSING TECHNOLOGY
·
2019
·
IF 4.507
Tao Xie,Jing-Pei Cao,Chen Zhu,Xiao-Yan Zhao,Ming Zhao,Yun-Peng Zhao,Xian-Yong Wei
Selectively cleaving the C O bonds in lignin to produce aromatic products are challenging problems. Currently, catalytic hydrogenolysis of C O bonds in lignin requires harsh conditions. Herein, selectively cleaving C O bond of benzyl phenyl ether (BPE) was studied over Pd/AC, Ru/AC and Ni/AC. Among these catalysts, Pd/AC efficiently cleaved C O bond in BPE under super mild conditions (25 °C, 2 h and 0.1 MPa H 2 ). The products were toluene and phenol without hydrogenation of the aromatic ring . The main competitive step of hydrogenolysis and hydrogenation is sensitive to reaction temperature over Pd catalyst. A mild temperature is preferred for hydrogenolysis, since the H species nearby the oxygen atom are more strongly adsorbed than nearby the benzene rings . With the different H-donor solvents, the highest conversion of BPE was obtained in isopropanol. Based on the experiments, the reactions occurred via cleavage of the C aliphatic -O bond in BPE and the synergetic effects between the H from absorbed H 2 on the surface of the Pd and the intermediates radicals of benzyl and phenoxy should be the key points to such an optimum result.
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 Materials & Interfaces
·
2024
·
IF 8.3
Shuchao Jiang,Hongqi Shi,Yuzhe Xu,Jiaojiao Liu,Tie Yu,Guoqing Ren
Formic acid (FA, HCOOH) is regarded as one of the most promising carriers for hydrogen storage. However, the catalyst design for FA dehydrogenation into H2 with high efficiency is not clear. Here, we elucidate the rationale of size effect over the most commonly used Pd-based catalyst through supporting different Pd species, including single atoms, nanoclusters, and nanoparticles, on amine-functionalized active carbon (Pd/AC-NH2). The activity test presents that Pd/AC-NH2 with Pd nanoclusters exhibits the best turnover frequency (TOF) value of 40856 h–1 for 1 M FA at 328 K and even 1504 h–1 for neat FA at 308 K, which is comparable to the homogeneous catalysts and has been the first heterogeneous catalyst used in neat FA dehydrogenation under mild conditions. The comprehensive characterizations reveal that the size of Pd species affects the ratios of Pd0/Pd2+ and hydrogen spillover effect, which is crucial for the C–H cleavage and H2 desorption. Besides, the influences of amine groups on catalytic performance were further examined. This work provided an ingenious guideline to design efficient and practical catalysts for hydrogen storage under ambient conditions.
研究领域:
化学工程
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材料科学
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能源科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Reaction Chemistry & Engineering
·
2022
·Vol. 7
·期 8
·1827-1835
·
IF 5.2
Zipin Peng,Xuepeng Wang,Zheng Li,Xingkun Chen,Yunjie Ding,Jisong Zhang
Catalytic hydrodechlorination (HDC) is considered to be a safe and effective method to treat chlorinated organic pollutants and has always been a hot spot in basic catalysis research. It is difficult to obtain excellent catalytic performance due to the inferior mass transfer performances of traditional batch reactors, and the deactivation of catalysts can easily occur due to the poisoning effect of HCl. In this work, Pd catalysts supported on activated carbon (Pd/AC) were synthesized by the ion-exchange (IE) method. The characterization results of N2 physisorption, XRD, TEM and XPS revealed that the active Pd components were uniformly dispersed on the surface of AC in the form of nanoparticles. A continuous flow system based on a micro-packed bed reactor (μPBR) was developed for the hydrodechlorination, and the hydrogenation of chlorobenzene (CB) was selected as the model reaction. With the optimal reaction conditions, a conversion and selectivity of 100% were obtained. Importantly, no obvious deactivation of the catalysts was observed during a 100 h time-on-stream test. Moreover, Pd/AC catalysts exhibited remarkable substrate suitability in dechlorination systems. The reaction kinetics for hydrodechlorination of CB in methanol was investigated after the internal and external diffusion limitations were eliminated.
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
危险品化学品经营许可证（带存储）