ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH
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2020
·Vol. 27
·期 24
·30243-30253
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IF 3.056
Xu Wenqing,Gao Lei,Yang Yang,Zhu Tingyu,Qi Guisheng
The deposition of NH 4 HSO 4 on catalysts is one of the key issues for selective catalytic reduction of NO x . In this study, NH 4 HSO 4 was preloaded on catalysts, and the effects of MoO 3 and CeO 2 doping on the decomposition and reactivity of NH 4 HSO 4 on V 2 O 5 /TiO 2 catalysts are studied. The results show that the introduction of MoO 3 and CeO 2 significantly promoted NO x conversion on the V 2 O 5 /TiO 2 catalysts. Doping with MoO 3 could effectively enhance the S and H 2 O resistance of the catalysts. Fourier transform infrared spectroscopy (FTIR) and X-ray photoelectron spectroscopy (XPS) analysis indicate that it is the strong chemical interactions between NH 4 HSO 4 and the catalysts that are adverse to the decomposition of NH 4 HSO 4 . However, doping with MoO 3 apparently inhibits these interactions, which significantly decrease the decomposition temperature of NH 4 HSO 4 . In situ FTIR experiments show that the NH 4 + in preloaded NH 4 HSO 4 could react with gaseous NO on catalysts, and doping with MoO 3 could facilitate the reaction rate.
研究领域:
环境科学
·
催化化学
✓ 已验证
DOI
PubMed
高影响因子
JOURNAL OF MOLECULAR CATALYSIS A-CHEMICAL
·
2015
·
IF 3.615
Jian Wang,Xue Wang,Xiaolong Liu,Junlin Zeng,Yangyang Guo,Tingyu Zhu
In this article, we present a detailed study combining the kinetic studies and in-situ FTIR experiments to investigate the oxidation behavior of chlorobenzene over V 2 O 5 /TiO 2 catalysts. The catalytic data show the 3–5 wt.% V 2 O 5 /TiO 2 catalysts are best fit for the oxidation of chlorobenzene. The calculated apparent reaction orders are about 0.6 and 0.2, respectively. The results of in-situ FTIR provided mechanism insights into the catalytic reaction, which supports the following proposal: (i) a nucleophilic substitution on V O species and (ii) attacking by surface oxygen through a electrophilic substitution, then (iii) followed by the cracking of ring structure, and further oxidation of the resulting species to form final products. The above results further suggest that the nucleophilic substitution process and surface reaction are kinetically significant steps for chlorobenzene oxidation, determining the overall rate of the reaction. Furthermore, 1,2-dichlorobenzene, 1,3-dichlorobenzene and 1,2,4-trichlorobenzene as additional reactants were tested together with chlorobenzene in binary mixtures to examine their competition reactions.
研究领域:
环境科学
·
催化化学
✓ 已验证
DOI
高影响因子
CATALYSIS COMMUNICATIONS
·
2018
·
IF 3.463
Xiaoqiang Gao,Fang Zhang,Yi Yu,Yonghui Dou,Li Xu,Guoji Liu
Mo-modified V 2 O 5 /TiO 2 catalysts were prepared by wetness impregnation method and investigated for the selective oxidation of 2-methylnaphthalene to 2-naphthaldehyde. The catalysts were characterized by XRD, BET, XPS, and Raman to investigate the promotional effect of Mo on catalyst structure, surface property, and catalytic performance. The introduction of molybdenum decreases the amount of KVO 3 phase and enhances the dispersion of the vanadium phase. XPS and Raman results indicate that Mo prevents Sn and K to interact with V species and bonds with Ti or V through bridge oxygen. V1Mo1 sample demonstrates a remarkable improvement in conversion and selectivity compared with others.
研究领域:
催化化学
·
材料科学
✓ 已验证
DOI
高影响因子
ENERGY & FUELS
·
2023
·
IF 5.3
Linghan Xia,Mengchen Wu,Yimeng Li,Hongyan Guo,Yonghong Cheng,Guodong Meng
As one of the most consensus goals around the world, reduction of carbon emissions has attracted huge attention from academic and industry communities for developing renewable energy sources and carbon capture techniques. Nonthermal equilibrium plasma catalysis has been proven to be a very promising way for CO2 conversion into high-value-added products; however, the synergistic catalytic mechanism between the plasma and various catalysts remains a challenge. In this work, we designed a reactor of atmospheric pressure glow discharge (APGD) plasma jet coupled with V2O5/TiO2 nanocomposite catalysts and studied the influence of V2O5 mass fraction, catalyst pretreatment, and reaction plasma parameters on the CO2 dissociation performance. Results showed that the designed reactor could introduce high-density plasma to the downstream area and maintain lower gas temperature, allowing the collaboration between APGD and the V2O5/TiO2 catalyst. The XRD analysis indicated that the solid solution phase TiVO4 could be formed in catalysts by V2O5 doping and reach a maximal content at a mass fraction of 30%, which determined the most excellent redox ability of the catalyst. The pretreatment of the as-prepared catalyst by Ar dielectric barrier discharge (DBD) plasma increased the oxygen vacancy density of the catalyst, thereby raising the conversion rate by 18.43%. Moreover, the transition regime between laminar and turbulent states was found to be the optimal configuration for CO2 dissociation. The reaction pathway was proposed for CO2 dissociation synergistically catalyzed by an APGD plasma jet and V2O5/TiO2. Ultimately, the maximum conversion of 14.88% and energy efficiency of 40.45% were simultaneously achieved, which were superior to the results of most atmospheric pressure plasmas. This work opens an avenue to develop plasma technology for sustainable CO2 utilization.
研究领域:
环境科学
·
材料科学
·
催化化学
✓ 已验证
产品关联
DOI
高影响因子
FUEL
·
2024
·
IF 6.7
Tingfeng Shan,Zhen Zhang,Bowen Li,Qi Zhang,Xiangfu Wang,Yusi He,Hongmin Yang
The utilization of commercial vanadium-titanium based catalysts (V 2 O 5 /TiO 2 ) within the selective catalytic reduction (SCR) process is a prominent contributor to the emergence of sulfur trioxide (SO 3 ) in coal-fired boiler environments. The direct modification of vanadium-titanium based catalysts has big potential to be an efficacious strategy for in-situ inhibiting SO 3 formation. This research evaluates the effectiveness of MoS 2 modified V 2 O 5 /TiO 2 catalyst on SO 2 oxidation under diverse conditions, using controlled condensation for SO 3 collection. The results showed that V 2 O 5 -MoS 2 /TiO 2 catalysts outperformed conventional V 2 O 5 /TiO 2 catalysts in inhibiting the oxidation from SO 2 to SO 3 between 200 and 400 °C, with optimal performance at 350 °C. No significant effect was observed on the catalytic oxidation of SO 2 when the O 2 concentration was lower than that of SO 2 , whereas the introduction of appropriate quantities of NO promoted the generation of SO 3 . The excessive inclusion of NH 3 nearly doubled the SO 3 generation rate, increasing it from 0.284 % to 0.434 %. The NO and NH 3 mixture markedly reduced SO 3 generation to 0.085 % at a 62 mL/min mixture concentration, just 30 % of the rate without the mixture. Following the reaction of SO 2 and O 2 , the reacted catalyst exhibited reduced pore volume, enhanced thermochemical stability, and lower susceptibility to SO 2 catalytic oxidation. The addition of low-valence sulfur improves catalyst reducibility, reduces V 5+ –OH reactions in various atmospheres, and decreases the formation of sulphate and gaseous SO 3 . The Mo-S-Mo group also effectively prevents the formation of HSO 4 − intermediates. Additionally, MoS 2 reacts with SO 3 via a reduction reaction, significantly lowering the SO 3 levels. Finally, in diverse atmospheric conditions, the catalysts maintained their V 5+ content and catalytic efficiency, thus improving SCR performance stability.
研究领域:
环境科学
·
催化
·
化学工程
·
能源技术
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）