Catalysts
·
2022
·Vol. 12
·期 11
·1430
·
IF 4.501
Yang Gao,Li Cao,Xiaodong Wu,Xu Zhang,Ziran Ma,Rui Ran,Zhichun Si,Duan Weng,Baodong Wang
CeNbTi catalyst was poisoned in different sulfur poisoning atmospheres at 300 °C for 6 h and then was evaluated for selective catalytic reduction (SCR) of NOxwith NH3. The catalyst deactivation upon SO2exposure was effectively inhibited in the presence of NH3. Temperature-programmed decomposition (TPD) analyses were applied to identify deposit species on the poisoned catalysts by comparison with several groups of reference samples. Diffuses reflectance infrared Fourier transform spectroscopy (DRIFTS) over CeNbTi catalysts with different poisoning pretreatments and gas purging sequences were designed to investigate the roles of NH3in the removal of surface sulfites and sulfates. More ammonium sulfates including ammonium bisulfate and ammonium cerium sulfate were generated instead of inert cerium sulfate in these conditions. The mechanisms about the formation and transformation of surface deposits upon sulfur poisoning w/wo NH3were explored, which provided a basis for developing Ce-based mixed oxides as SCR catalysts for stationary sources.Keywords:ceria;SCR;sulfur;NH3;TPD;DRIFTS;deposit
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
JOURNAL OF HAZARDOUS MATERIALS
·
2020
·
IF 9.038
Kejian Li,Xiaozhong Fang,Zhaoyang Fu,Yang Yang,Iqra Nabi,Yiqing Feng,Aziz-Ur-Rahim Bacha,Liwu Zhang
Sulfite is recently found to be promising in enhancing photocatalytic pollutants degradation, which is a byproduct from flue gas desulfuration process. Herein, 4-chlorophenol (4-CP) photodegradation was systematically investigated in a sulfite mediated system with g-C 3 N 4 as photocatalyst. The degradation efficacy was improved by about 3 times with addition of 25 mM Na 2 SO 3 . The dominant responsible reactive oxygen species for chlorophenols remediation in the presence of sulfite included O 2 ·− , SO 3 ·− , and SO 4 ·− as confirmed by radical quenching experiments and electron spin resonances technology. In-situ DRIFTs results indicated the improved cleavage of C Cl and C H bonds with the simultaneous formation of C O and C C bonds when bisulfite was added. Degradation intermediates such as 4-chlorocatechol, hydroquinone, and muconic acid were detected by HPLC-MS. Furthermore, the photodegradation mechanisms of 4-CP were tentatively discussed . Other chlorophenols (phenol, 2-CP, 2,4-DCP, and their mixture) were also efficiently removed in the system, suggesting that sulfite could be universally applied in photocatalytic wastewater purification.
研究领域:
环境科学
·
化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
FUEL
·
2023
·
IF 7.4
Deng Zhao,Haoyuan Feng,Yu Wang,Fei Wang,Huashan Wang,Hua Liu,Hui Liu
The influence mechanism of alkali metal potassium (K) on cellulose pyrolysis is a vague and fundamental key topic in the field of biomass thermal conversion. In this study, the pyrolysis of cellulose and K-impregnated cellulose was compared by in-situ DRIFTS (Diffused Reflectance Infrared Fourier Transform Spectroscopy) and TG (Thermal Gravimetric)–MS (Mass Spectrum) experiment, and quantum chemical calculations were used to verify the peak position and pyrolysis mechanism of infrared (IR) spectroscopy. Stepwise isothermal in-situ DRIFTS was designed to study the reaction path at high temperatures. It was found that in the early stage of pyrolysis, K accelerated the activation of cellulose by attacking the hydrogen bond (H-bond) in the crystal structure of cellulose, increased the dehydration rate between molecules, and promoted the decomposition of cellulose. Simultaneously, it weakened the epoxy–ether bond, inhibited the formation of dehydrated sugar, and promoted the formation of furan. Subsequently, K combined with carbonyl groups to form C–O–K structures, which improved the thermal stability of certain oxygen-containing functional groups such as carbonyls/aldehydes, so that these structures were retained until higher temperature. K promoted the conversion of dehydrated sugars to straight-chain ketones/aldehydes, which led to an increase in carbon conversion. During the coke generation stage, K promoted the formation of disordered carbon and residues, thereby inhibiting coke aromatization. The isothermal in-situ DRIFTS method proposed in this study was demonstrated to better inhibit the high temperature drift of IR spectrum during pyrolysis. It clarified the conversion between functional groups at high temperatures, which is expected to promote the development of other high-temperature pyrolysis mechanism.
研究领域:
生物质能
·
热化学转化
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产品关联
DOI
高影响因子
Catalysis Science & Technology
·
2021
·Vol. 11
·期 15
·5125-5134
·
IF 6.119
Yanke Yu,Xianfang Yi,Jiali Zhang,Zhaojian Tong,Changwei Chen,Mudi Ma,Chi He,Jinxiu Wang,Jinsheng Chen,Bingbing Chen
Non-vanadium-based catalysts with high SO2 tolerance are still interesting in selective catalytic reduction of NO by NH3 (NH3-SCR) and SO2 adsorption is the foremost step for the deactivation of catalysts. In order to alleviate the adsorption of SO2, we fabricated a series of rhenium (Re; without stable sulfate) supported TiO2 catalysts and studied their SO2 tolerance for the first time. Owing to suitable surface acidity and reducibility, ReOx/TiO2 catalysts exhibited satisfactory activity in a wide temperature range of 250–350 °C. As expected, experimental results and DFT calculations indicated that SO2 adsorption on ReOx/TiO2 catalysts was rather weak, thus the catalysts performed excellent SO2 tolerance in the NH3-SCR reaction. Moreover, in situ DRIFTS indicated that the NH3-SCR reaction on ReOx/TiO2 catalysts followed the Eley–Rideal mechanism and SO2 had little effect on the reaction mechanism. Our findings should provide new insights into the development of SCR catalysts with high SO2 tolerance.
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
ENERGY & FUELS
·
2025
·
IF 5.3
Fang Wang,Xueyan Wu,Yuxuan Han,Yan Lv,Jixi Guo,Xiaoman Li,Yaping Zhang
In cement kiln flue gas emissions, high concentrations of alkali and alkaline earth metals cause the deactivation of the NbCe/Ti catalysts, significantly reducing their operational lifespan under industrial conditions. Here, the NbCe-loaded titanium nanotubes (NbCe/TiNTs) catalyst has been synthesized via hydrothermal and impregnation methods. The NbCe/TiNTs catalyst exhibits superior resistance to potassium (K) and calcium (Ca) poisoning. Notably, NbCe/TiNTs catalyst maintains high NOx conversion across a wide temperature range (192–350 °C). The 5Ca-NbCe/TiNTs and 3K-NbCe/TiNTs catalysts achieve a 90% NOx conversion at 235 and 242 °C, respectively, demonstrating remarkable resistance to K and Ca poisoning. The results indicate that TiNTs supports enhance both the specific surface area and surface acid sites of the catalyst, synergistically improving its resistance to K and Ca poisoning. Furthermore, an in situ diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) study elucidates selective catalytic reduction with the NH3 (NH3-SCR) reaction mechanism, revealing dual contributions from both the Eley–Rideal (E–R) and Langmuir–Hinshelwood (L–H) mechanisms on the catalyst. This work provides a research direction for enhancing the alkali poisoning resistance of NOx removal catalysts.
研究领域:
环境催化
·
材料科学
·
化学工程
·
表面科学
✓ 已验证
产品关联
DOI
高影响因子
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
·
2026
·
IF 3.9
Leiting Kuai,Xuan Meng,Naiwang Liu,Li Shi
This study aims to elucidate the reaction mechanism of naphthalene alkylation with long-chain α-tetradecene (α-C14H28) over H-FAU zeolite, a reaction critical for producing high-value alkylated aromatics in industrial catalysis. By combining in situ diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) with kinetic and thermodynamic analysis, this study quantitatively tracks the evolution of four key carbocation intermediates formed on distinct Brønsted acid sites and identifies the Wheland-intermediate-forming step as rate-determining. For the first time, adsorption and diffusion analysis, reaction kinetics, and comprehensive catalyst characterization (XRD, NH3-TPD, pyridine-IR) are integrated to establish a complete mechanistic pathway. The results reveal how pore confinement and acid-site distribution govern intermediate evolution and overall activity, thereby offering a validated model for the rational design of selective and stable zeolite catalysts for continuous alkylation processes.
✓ 已验证
DOI
高影响因子
Molecular Catalysis
·
2023
·
IF 4.6
Tiantian Zhang,Jiacheng Xu,Yan Sun,Shiyu Fang,Zuliang Wu,Erhao Gao,Jiali Zhu,Wei Wang,Lianxin Dai,Weihua Liu,Buhe Zhang,Junwei Zhang,Shuiliang Yao,Jing Li
Nano-Au has a good catalytic activity for CO oxidation, but its catalytic mechanism is still not clear. Here, CO oxidation on Au 2 O 3 and its thermal decomposition products were studied using thermogravimetric-mass spectrometry (TG-MS) and operando diffuse reflectance infrared Fourier transform spectroscopy-mass spectrometry (DRIFTS-MS) to explore the key active components of Au catalyst for CO oxidation. The TG-MS results showed that Au 2 O 3 decomposed to AuO at 210 °C and Au at 375 °C and was oxidized to form Au oxide above 375 °C. When Au 2 O 3 decomposed into Au x O y (x>y) above 210 °C, the CO oxidation activity obviously increased. Au atoms in the Au-Au system serve as electron donor and CO adsorption sites. Au atom is oxidized to AuO by the O atom from O 2 decomposition following the Epling-Xu decomposition mechanism. A schematic diagram of the key components of Au 2 O 3 catalysts during CO oxidation was proposed based on TG-MS and operando DRIFTS-MS analysis results.
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
FUEL
·
2022
·
IF 8.035
Yihua Yue,Zhongliang Huang,Dongren Cai,Shafqat Ullah,Abdul-Rauf Ibrahim,Xin Yang,Jiale Huang,Guowu Zhan
Controlled fabrication of spatial positions of different active sites on catalyst structures is critical to exploring the reaction mechanisms for CO 2 hydrogenation. Herein, two isomorphous zeolitic imidazolate frameworks (ZIF-67 and ZIF-8) were used as sacrificial templates to synthesize multi-layered Co 3 O 4 /ZnO catalysts with tunable core-shell structures and well-controlled spatial positions. The multi-layered catalysts were then evaluated for the catalytic performance for CO 2 hydrogenation. A series of characterization techniques were applied to investigate the morphology and structure of the Co 3 O 4 /ZnO composites with different spatial locations. Due to the unique multi-layered structure, the distinct interfacial structures, and the synergistic effects, the resultant core-shell structured Co 3 O 4 /ZnO nanocatalysts exhibited significantly enhanced activity as compared to their monometallic counterparts (pure Co 3 O 4 and ZnO). In addition, the ZnO@Co 3 O 4 with Co 3 O 4 as shell showed significantly higher CO 2 conversion (25%) than that of Co 3 O 4 @ZnO with ZnO as shell (0.82%). Furthermore, in-situ Diffuse Reflection Fourier Transform Infrared Spectroscopy (DRIFTS) analysis suggested that formate (HCOO*) and methoxy (CH 3 O*) species were the crucial intermediates in the CO 2 hydrogenation over the Co 3 O 4 /ZnO composite nanocatalysts. However, pure ZnO could not activate the CO 2 ; consequently, the use of the Co 3 O 4 /ZnO nanocatalysts derived from multiple-layered ZIFs structures provides new insights into improving the catalytic efficiency of CO 2 hydrogenation.
研究领域:
催化化学
·
材料科学
·
环境科学
✓ 已验证
DOI
高影响因子
APPLIED CATALYSIS B-ENVIRONMENTAL
·
2023
·
IF 22.1
Decun Luo,Ziyu Tang,Xiyang Yu,Tao Zhang,Chun-Ran Chang,Zhun Hu
The effect of ZrO 2 crystalline phases on Pd/ZrO 2 for catalytic combustion of toluene was investigated. It was found that Pd/t-ZrO 2 showed superior activity when the toluene concentration was lower than 2000 ppm, while Pd/m-ZrO 2 performed better with toluene concentration higher than 3000 ppm. Kinetic studies showed that the reaction order of toluene on Pd/t-ZrO 2 and Pd/m-ZrO 2 is 0 and 2, respectively. The catalytic activity was controlled by combined effect of PdO activity and quantity, which was correlated with the interaction between palladium and zirconia. The t-ZrO 2 increased PdO species activity, while m-ZrO 2 could enhance the amount of PdO. DFT results showed that the p-band center of the O of PdO on t-ZrO 2 was higher, suggesting that PdO was more active. In situ -DRIFTS revealed that the reaction pathway of catalytic oxidation of toluene on Pd/ZrO 2 was as follows: toluene was oxidized stepwise to benzyl alcohol, benzaldehyde, benzoic acid , CO 2 and H 2 O.
研究领域:
催化化学
·
环境科学
·
材料科学
✓ 已验证
DOI
高影响因子
ChemCatChem
·
2023
·Vol. 15
·期 7
·e202300194
·
IF 4.5
Tao Li,Mengling Dong,Jiacheng Xu,Tiantian Zhang,Yan Sun,Ning Li,Zuliang Wu,Jing Li,Erhao Gao,Jiali Zhu,Shuiliang Yao,Yong Huang
Graphical CeO 2 /γ-Al 2 O 3 , Pd/CeO 2 , and Pd/CeO 2 /γ-Al 2 O 3 were used for catalyzing low-concentration CH 4 oxidation . γ-Al 2 O 3 can efficiently promote CH 4 oxidation on Pd/CeO 2 and the formation of bicarbonate that is easily gasified to CO 2 . CeO 2 /γ-Al 2 O 3 , Pd/CeO 2 , and Pd/CeO 2 /γ-Al 2 O 3 were used for catalyzing low-concentration CH 4 oxidation. It was found that nano-sized Pd could obviously promote CH 4 oxidation on CeO 2 /γ-Al 2 O 3 . The interaction between Pd and CeO 2 on γ-Al 2 O 3 resulted in higher ratios of Ce 3+ /(Ce 3+ +Ce 4+ ), Pd 2+ /(Pd 2+ +Pd δ+ ), and O ads /(O ads +O latt ), those benefited the formation of more oxygen vacancies and surface reactive oxygen species for CH 4 oxidation. γ-Al 2 O 3 not only supplied a high surface area and enhanced Pd/CeO 2 dispersion on γ-Al 2 O 3 , but also simulated the formation of bicarbonate, where bicarbonate is easier to gasify to CO 2 than bidentate carbonate that formed on Pd/CeO 2 . Operando diffuse reflectance infrared Fourier transform spectroscopy-mass spectrometer analysis results showed that CH 4 oxidation could occur at a temperature as low as 180 °C due to the reaction with surface reactive OH, this reaction was also accompanied by the formation of bicarbonate. The mechanism of CH 4 oxidation promoted by bicarbonate formation on γ-Al 2 O 3 was proposed.
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
ATMOSPHERIC ENVIRONMENT
·
2023
·
IF 5
Xiang He,Aiyilaiti Kudesi,Shuangxi Wang,Xin Liu,Lin Hu
Heterogeneous reactions of toluene/NO 2 with and without O 3 on α-Fe 2 O 3 particles was studied as a function of temperature by using in situ diffuse reflectance infrared Fourier transform spectrometry (DRIFTS). The results show that the formation of R-ONO 2 group is identified on the α-Fe 2 O 3 particles surface, indicating the formation of benzyl nitrate in the presence of toluene/NO 2 with or without O 3 at different temperatures from 253 K to 298 K. From the analysis of the spectral changes, the reaction kinetics, such as reaction rate and uptake coefficient are sensitive to temperature. During the heterogeneous reaction of toluene/NO 2 , the formation rate of organic nitrate increases from (2.38 ± 0.07) × 10 17 ions g −1 s −1 to (5.95 ± 0.09) × 10 17 ions g −1 s −1 when the temperature decreases from 278 K to 253 K. When the trace gases were toluene/NO 2 /O 3 , the reaction rate increases about 3 folds with the increasing of temperature from 253 K to 298 K. In the absence of ozone, nitrification from heterogeneous reaction is exothermic process. However, the addition of ozone dominates the whole reaction process, resulting the different change trends of formation rate at similar range of temperatures. Furthermore, reactive uptake coefficient increases from (6.73 ± 0.02) × 10 −7 to (1.64 ± 0.05) × 10 −6 with decreasing temperature from 278 K to 253 K during the heterogeneous reaction of toluene/NO 2 on α-Fe 2 O 3 particles. The values of activation energy for the heterogeneous reaction of toluene/NO 2 and toluene/NO 2 /O 3 are determined to be −8.60 ± 0.91 kJ mol −1 and 15.14 ± 2.51 kJ mol −1 , respectively. It implies that the heat change is an important factor in affecting the heterogeneous reaction under the seasonal temperature changes.
研究领域:
大气化学
·
环境科学
✓ 已验证
产品关联
DOI
高影响因子
Materials
·
2023
·Vol. 16
·期 11
·4010
·
IF 3.4
Su Zhang,Baoyu Huang,Zenghao Jiang,Junfan Qian,Jiawei Cao,Qiuxia Feng,Jianwei Zhang,Xiaogan Li
Au modified TiO2/In2O3hollow nanospheres were synthesized by the hydrolysis method using the carbon nanospheres as a sacrificial template. Compared to pure In2O3, pure TiO2, and TiO2/In2O3based sensors, the Au/TiO2/In2O3nanosphere-based chemiresistive-type sensor exhibited excellent sensing performances to formaldehyde at room temperature under ultraviolet light (UV-LED) activation. The response of the Au/TiO2/In2O3nanocomposite-based sensor to 1 ppm formaldehyde was about 5.6, which is higher than that of In2O3(1.6), TiO2(2.1), and TiO2/In2O3(3.8). The response time and recovery time of the Au/TiO2/In2O3nanocomposite sensor were 18 s and 42 s, respectively. The detectable formaldehyde concentration could go down as low as 60 ppb. In situ diffuse reflectance Fourier transform infrared spectroscopy (DRIFTS) was used to analyze the chemical reactions on the surface of the sensor activated by UV light. The improvement in the sensing properties of the Au/TiO2/In2O3nanocomposites could be attributed to the nanoheterojunctions and electronic/chemical sensitization of the Au nanoparticles.Keywords:Au modified TiO2/In2O3hollow nanospheres;room temperature formaldehyde sensors;UV activation;in situ DRIFTS
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）