http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
Controllable synthesis of zone-distributed Pd over CeO2–ZrO2/Al2O3 as advanced three-way catalyst
Li Lan,Shanhu Chen,Hongmei Li,Hanmei Li,Wanxia Wu,Jie Deng,Yaoqiang Chen 한국공업화학회 2018 Journal of Industrial and Engineering Chemistry Vol.58 No.-
Two optimally designed catalysts (Ce0.7Zr0.3O2/Pd/Al2O3, Pd/Ce0.7Zr0.3O2/Pd/Al2O3) were synthesized and compared with conventional Pd/Ce0.7Zr0.3O2/Al2O3. The characterization results reveal that for Pd/Ce0.7Zr0.3O2/Al2O3, Pd species undergo severe agglomeration and encapsulation during thermal aging process, leading to dramatic catalyst deactivation. While for the two optimized catalysts, some Pd species initially distributed on Al2O3 would migrate to the surface of CexZr1−xO2(CZ) grains upon aging treatment, resulting in enhanced Pd–CZ interaction, thus the two aged samples possess higher dispersion, larger amount of oxidized Pd2+ species and more oxygen vacancies compared with conventional Pd/Ce0.7Zr0.3O2/Al2O3-a. Consequently, modified reducibility and improved three-way catalytic performance are obtained, especially for Pd/Ce0.7Zr0.3O2/Pd/Al2O3-a.
Li Lan,Jinfeng Wang,Shanhu Chen,Dacheng Li,Hongmei Li,Dayu Liu,Wei Wang,Yaoqiang Chen 한국공업화학회 2019 Journal of Industrial and Engineering Chemistry Vol.71 No.-
In this work, an advanced Rh/CeO2–ZrO2 (Rh/CZ) three-way catalyst was synthesized with the assistanceof monoethanolamine. Compared with conventional Rh/CZ, the dispersion and oxidation state of Rhspecies, as well as the hydrothermal aging resistance are remarkably modified. That is, upon agingtreatment, conventional Rh/CZ undergoes severe agglomeration of Rh species and formation of largeamount of reduction-resistive RhO2, resulting in serious catalyst deactivation. Fortunately, after theintroduction of monoethanolamine, the sintering of Rh species and transformation into inactive RhO2upon aging are effectively suppressed. Consequently, improved reducibility and advanced three-waycatalytic activity are achieved for the modified catalyst.
Yajuan Cui,Li Lan,Zhonghua Shi,Shandong Yuan,Yaoqiang Chen,Yi Dan 한국공업화학회 2018 Journal of Industrial and Engineering Chemistry Vol.60 No.-
Three ceria-zirconia solid solutions were prepared by different synthesis routes. The results showed that CZ3 exhibited incompact structure with heterogeneous particle size distribution, accompanied by a bimodal pore size distribution. After aging treatment, the specific surface area and cumulative pore volume of CZ3-a were 37 m2/g and 0.22 cm3/g, which decreased by only 51% and 4% respectively from the fresh state. And the particle volume increased by only 4 times. Among the three samples, the textural/structural properties of CZ3 showed the smallest degradation, indicating the highest thermal stability, which was attributed to the incompact structure and special texture.
Hydrothermal deactivation over CuFe/BEA for NH3-SCR
Qingjin Lin,Xi Feng,Hailong Zhang,Chenlu Lin,Shuang Liu,Haidi Xu,Yaoqiang Chen 한국공업화학회 2018 Journal of Industrial and Engineering Chemistry Vol.65 No.-
Hydrothermal deactivation over CuFe/BEA and CuFe/BEA-HT for the selective catalytic reduction of NO with NH3 (NH3-SCR) were investigated with different characterizations. The hydrothermal treatment destroys BEA skeleton, losing acid sites reacting with the aerial NOx. H2-TPR and XPS reveal that the hydrothermal treatment could weaken the interaction between Cu/Fe species and the surrounding other atoms, causing the aggregation of isolated and low nuclearity copper/iron species. Aggregated copper/iron oxides depress the redox property of CuFe/BEA-HT, producing the lower concentration of NO2. Besides, results of in situ DRIFTS also indicate that both CuFe/BEA and CuFe/BEA-HT follow Eley–Rideal (E–R) mechanism at 225 °C.
Jie Deng,Yi Zhou,Shanshan Li,Lei Xiong,Jianli Wang,Shandong Yuan,Yaoqiang Chen 한국공업화학회 2018 Journal of Industrial and Engineering Chemistry Vol.64 No.-
Three CeO2–ZrO2–Y2O3–La2O3 (CZ) nanomaterials with controllable crystallite size were prepared by a simple co-precipitation method combined with hydrothermal treatment at different temperatures. The material CZ-180 possesses a high surface area of 43.6 m2 g−1 and a low reduction temperature of 344 °C simultaneously even after aging at 1000 °C for 4 h. Moreover, with improving hydrothermal temperature, the incorporation of rear earth metals was accelerated and surface properties were modified. And higher Pd dispersion and larger proportion of active Pd2+ species were achieved on the modified surface of CZ-180. Consequently, the supported catalyst Pd/CZ-180 shows a superior three-way catalytic performance.
Yanli Liang,Ming Zhao,Jianli Wang,Mengmeng Sun,Shanshan Li,Yufen Huang,Lin Zhong,Maochu Gong,Yaoqiang Chen 한국공업화학회 2017 Journal of Industrial and Engineering Chemistry Vol.54 No.-
A series of the modified Pt/SiO2–Al2O3 diesel oxidation catalysts with different WO3 loading were prepared through co-impregnation method. With an optimum additive loading of 2 wt% WO3, the catalyst significantly improved the performance and its stability. Compared to the free-tungsten sample, the catalyst increased the maximum conversion of NO by 5–10% and decreased the reaction temperature for 30% NO conversion by 7–28 C. It was found that there exist the electron and structure interaction between platinum and tungsten species. The interactions can generate and maintain more Pt sites in metallic state for the catalytic oxidation with enhanced activity and stability.
Haidi Xu,Yuanshan Li,Baoqiang Xu,Yi Cao,Xi Feng,Mengmeng Sun,Maochu Gong,Yaoqiang Chen 한국공업화학회 2016 Journal of Industrial and Engineering Chemistry Vol.36 No.-
FeWx/Ce0.68Zr0.32O2 (x = 0, 0.35, 0.7, 1.03, 1.38) catalysts with different molar ratios (x) of W/Fe wereprepared for NH3-SCR. The experimental results showed that catalytic performances of catalysts wereobviously improved by adjusting the molar ratio of W/Fe. FeW1.03/Ce0.68Zr0.32O2 catalyst with W/Fe of1.03 displayed the best catalytic performance, it could obtain higher than 95% NOx conversion and nearly100% N2 selectivity in the temperature range of 250–435 8C. The characterization results indicated thatmore active species of Fe3+, chemical adsorbed oxygen species and surface acid sites would togethercontribute to the excellent NH3-SCR performance of FeW1.03/Ce0.68Zr0.32O2 catalyst.