FUEL
·
2024
·
IF 6.7
Qitong Xue,Jiaying Xing,Jianjun Chen,Jinxing Mi,Jianqiang Shi,Yao Wang,Junhua Li,Zhiming Liu
V 2 O 5 /TiO 2 has been wide used in the selective catalytic reduction of NO x by NH 3 (NH 3 -SCR). However, the poisoning mechanism of thallium (Tl) on the catalytic performance of commercial V 2 O 5 /TiO 2 catalyst has remained unclear. Herein, we have systematically investigated the poisoning effect of Tl based on the different characterizations and DFT calculations. It was found that the strong interaction between V and Tl exists, resulting in the transformation of V from monomeric VO x to polymeric and crystalline VO x , the formation of V-O-Tl species, a decrease in the active V 5+ sites, and the inhibition of the adsorption and activation of NH 3 on both Brønsted and Lewis acid sites. Mechanistic studies further confirmed that inactive nitrate intermediate species gradually accumulated over V 2 O 5 /TiO 2 catalyst surface due to the presence of Tl. A combination of factors ultimately led to the deactivation of the V 2 O 5 /TiO 2 catalyst. This study unveils the poisoning mechanism of Tl on V-based catalysts and shed light on the design of Tl-tolerant NH 3 -SCR catalysts.
研究领域:
环境科学
·
催化化学
✓ 已验证
DOI
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
ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH
·
2020
·Vol. 27
·期 24
·30243-30253
·
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
ENVIRONMENTAL SCIENCE & TECHNOLOGY
·
2023
·
IF 11.4
Jiaying Xing,Qitong Xue,Jianjun Chen,Jinxing Mi,Xiaoping Chen,Jianqiang Shi,Zhiming Liu,Junhua Li
Vanadium-based catalysts play a pivotal role in the emission control of industrial NOx via selective catalytic reduction (SCR) technology. However, little attention has been paid to the potential emission of greenhouse gas N2O under complex working conditions. This work reports that a commercial V2O5/TiO2 catalyst may lead to significant N2O emission without greatly changing the outlet NOx concentration after chromium (Cr) deposition. With a Cr loading of 2 wt %, N2O concentration increased from 27.8 to 199.2 ppm at 350 °C with the value of outlet N2O/(N2O+N2) from 2.5% to 19.4%. Experimental results combined with DFT+U calculations suggest that nonselective catalytic reduction (NSCR) is the main route for N2O formation in a wide temperature range of 250 ∼ 400 °C. It is stemmed from the fact that the covalent interaction between Cr and V species on the V2O5/TiO2 surface accelerates the conversion of V4+ + Cr6+ → V5+ + Cr3+, leading to a larger proportion of surface V5+. More importantly, surface V5+ is highly related to the redox property of the V2O5/TiO2 catalyst, which is beneficial to NSCR reaction rather than the standard SCR process. The work suggests that to better inhibit the emission of greenhouse gases during the NH3–SCR process, monitoring N2O emission should be included along with the NOx concentrations, especially in complex flue gases.
研究领域:
环境科学
·
催化化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
CHINESE JOURNAL OF CATALYSIS
·
2015
·
IF 1.964
Xin Zhao,Lei Huang,Hongrui Li,Hang Hu,Jin Han,Liyi Shi,Dengsong Zhang
Different transition metals were used to modify V 2 O 5 -based catalysts (M-V, M = Cu, Fe, Mn, Co) on TiO 2 via impregnation, for the selective reduction of NO with NH 3 . The introduced metals induced high dispersion in the vanadium species and the formation of vanadates on the TiO 2 support, and increased the amount of surface acid sites and the strength of these acids. The strong acid sites might be responsible for the high N 2 selectivity at higher temperatures. Among these catalysts, Cu-V/TiO 2 showed the highest activity and N 2 selectivity at 225–375 °C. The results of X-ray photoelectron spectroscopy, NH 3 -temperature-programmed desorption, and in-situ diffuse reflectance infrared Fourier transform spectroscopy suggested that the improved performance was probably due to more active surface oxygen species and increased strong surface acid sites. The outstanding activity, stability, and SO 2 /H 2 O durability of Cu-V/TiO 2 make it a candidate to be a NO x removal catalyst for stationary flue gas.
研究领域:
催化化学
·
环境科学
✓ 已验证
产品关联
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
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
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
JOURNAL OF INDUSTRIAL AND ENGINEERING CHEMISTRY
·
2026
·
IF 7.1
Lilong Zhou,Chuanshi Tan,Haichao Jiang,Yanchao Qu,Ying Zhang,Yongzhao Zhang,Jimmy Yun
To develop efficient catalysts for chlorinated VOC combustion with enhanced chlorine resistance, V–TiO 2 solid-solution catalysts were prepared via the sol–gel (SG) method and evaluated for chlorobenzene oxidation. In contrast to those synthesized by hydrothermal (HT) and impregnation (IM) methods, the SG-derived V–TiO 2 formed a solid solution with abundant V–O–Ti bonds and V 2 O 5 –TiO 2 interfaces. The TiO 2 acts as an electron donor to V 5+ , promoting oxygen vacancy formation, which facilitates oxygen adsorption and activation. As the amount of incorporated vanadium increases, the activity of the V–TiO 2 catalyst exhibits a volcanic pattern, indicating that constructing an appropriate amount of V 2 O 5 –TiO 2 interface is the key to improving the low-temperature activity of the V–TiO 2 catalyst. The SG-prepared V 2 O 5 /TiO 2 achieved 90% chlorobenzene conversion at 250 °C (GHSV = 22,500 h −1 , C = 1000 ppm), which is significantly lower than previously reported V 2 O 5 /TiO 2 catalysts. There were only a few kinds of byproducts and no chloride organic byproducts were generated. The catalyst also exhibited excellent stability and water resistance. This work offers an effective strategy for designing stable catalysts for chlorinated VOC combustion.
✓ 已验证
DOI
高影响因子
ACS Applied Nano Materials
·
2019
·
IF 0
Chunlei Zhang,Ping Wu,Guojuan Liu,Zhigao Zhu,Gaofeng Zeng
Direct oxidation of methanol to high value oxygenated chemicals on V2O5/TiO2 based catalysts is a green alternative to the commercial methods. But the V–Ti based catalysts are challenged by the relatively low reactivity. Herein, we demonstrated a facile and practicable strategy to directly fabricate hollow structure VOx/TiO2 nanofibers (VTO-HNF) through the coelectrospinning and calcination method. The effects of V/Ti ratio on the structure, the surface chemistry and methanol oxidation performance were investigated in detail. VTO-HNFs with appropriate V/Ti ratio have hierarchical structure, large surface area, uniform nanoparticles, narrowed grain sizes, and high dispersions of vanadium. Moreover, both the oxidation properties and the acidities of the catalyst were enhanced due to the high content of surface V4+. The VTO-HNF catalysts featured excellent activities and reliable stability for the selective oxidation of methanol to methyl formate (MF) and dimethoxymethane (DMM). The MF yield reached 90% at 150 °C, which is comparable with the noble metal based catalysts. In situ NAP-XPS investigations suggested that the variable valence of vanadium was involved in the oxidation of methanol.
研究领域:
材料科学
·
催化
·
化学工程
✓ 已验证
产品关联
DOI
CHEMICAL ENGINEERING JOURNAL
·
2026
·
IF 12.5
Lingqin Meng,Lu Wei,Duan Zhang,Jialong Wang,Yali Wang,Suping Cui
Tl poisons VTi catalysts by forming stable V-O-Tl bonds at V O active sites. • WO 3 provides steric shielding and acts as a sacrificial trap for Tl species. • WO 3 drives the electronic oxidation of highly toxic Tl + to less harmful Tl 3+ . • Optimized VWTi catalysts retain ~80% NO x conversion under cement kiln flue gas. Thallium (Tl), an extremely toxic and highly volatile heavy metal, has become the primary cause of rapid deactivation of V 2 O 5 /TiO 2 (VTi) SCR catalysts used in cement kilns. Industrial post-operation analyses consistently show exceptional Tl enrichment on catalyst surfaces—often 2–3 orders of magnitude higher than other heavy metals—resulting in a sharp decline in NO x removal efficiency and raising significant environmental and operational hazards. Motivated by real industrial observations that appropriate amounts of WO 3 substantially enhance the Tl tolerance of VTi catalysts, this study provides a mechanistic explanation for both the poisoning pathway and the mitigation effect. We demonstrate that Tl deactivation originates from its strong affinity for V O active sites, where it forms stable V-O-Tl bonds that collapse Lewis acidity, suppress oxygen-vacancy regeneration, and disrupt the V 5+ /V 4+ redox cycle essential for SCR activity. Through multi-scale characterization and DFT analysis, we reveal that WO₃ alleviates Tl toxicity through a dual synergistic mechanism: steric shielding that limits Tl access to vanadium centers, and oxidation of mobile Tl + to less reactive Tl 3+ , thereby weakening its ability to bind and deactivate V sites. This cooperative electronic-structural modulation preserves both acidity and redox functionality under realistic high-Tl exposure. The mechanistic insights presented here offer a rational foundation for developing durable, Tl-resistant SCR catalysts tailored for hazardous flue gas environments in cement and waste-incineration industries.
✓ 已验证
DOI
高影响因子
Nanomaterials
·
2022
·Vol. 12
·期 10
·1776
·
IF 5.719
Wentao Xu,Guoqiang Shu,Shihui Zhang,Lei Song,Kui Ma,Hairong Yue
Titanium dioxide is a mainstream photocatalyst, but it still confronts great obstacles of poor visible light absorption and rapid recombination rate of photogenerated carriers. Herein, we describe the design of a highly active visible-light photocatalytic system of graphited carbon layers anchored V2O5/TiO2heterojunctions derived from Ti3C2MXene, which demonstrates about 4.58 and 2.79 times higher degradation activity of MB under visible light (λ > 420 nm) than pure V2O5and TiO2-carbon. Combined with the characterization results, the formed V2O5/TiO2heterojunction promotes the separation of photogenerated carriers, while the graphitized carbon derived from MXene acts as an electronic reservoir to enhance the absorption of visible light. The ESR results show that superoxide radicals and hydroxyl radicals are the main active species in the reaction system. Therefore, we propose a possible mechanism model to provide a feasible idea for the subsequent design of high-efficiency photocatalysts for environmental treatment.Keywords:MXene;heterojunction;degradation;visible light;photocatalysis
研究领域:
材料科学
·
环境科学
✓ 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）