CATALYSIS COMMUNICATIONS
·
2022
·
IF 3.51
Baohuai Zhao,Baofang Jin,Xiaodong Wu,Duan Weng,Rui Ran
A series of Sm-Mn oxides (SmMnO 3 , SmMn 2 O 5 and Sm 0.9 Ag 0.1 Mn 2 O 5 ) of perovskite-type and mullite crystal phases were synthesized for the catalytic oxidation of CO and C 3 H 8 . The Sm 0.9 Ag 0.1 Mn 2 O 5 composition showed the highest catalytic activity among the series of solids, especially for the CO oxidation to CO 2 with T 50 and T 90 values of 60 and 95 °C, respectively. The catalysts were characterized by powder XRD, Raman, BET, XPS, and H 2 -TPR. It was found that the catalytic performance of the solids was correlated well with their redox properties. Synergetic effects between Ag-related species and the mullite phase resulted in more active surface oxygen species and remarkably lowered the reduction temperature of the Sm 0.9 Ag 0.1 Mn 2 O 5 solid.
研究领域:
材料科学
·
催化化学
✓ 已验证
产品关联
DOI
高影响因子
ACTA PHYSICO-CHIMICA SINICA
·
2023
·
IF 10.9
Ruijie Zhu,Leilei Kang,Lin Li,Xiaoli Pan,Hua Wang,Yang Su,Guangyi Li,Hongkui Cheng,Rengui Li,Xiao Yan Liu,Aiqin Wang
Catalytic oxidation is a commonly employed technology in the industry for removing volatile organic compounds (VOCs) due to its exceptional efficiency under mild operating conditions. Although supported Pt-based nano-catalysts are recognized widely as one of the most promising and extensively used industrial catalysts for VOC abatement, their practical application, and development are restricted by their exorbitant cost. Single-atom catalyst (SAC) with maximized metal utilization and exclusive electronic character has been explored extensively in various catalytic reactions. However, Pt SAC is usually deemed to be inactive in hydrocarbon oxidation reactions in thermal catalysis, compared with its nanoparticle counterpart. Here, we demonstrate that the WO 3 -TiO 2 supported Pt SAC (Pt 1 /WO 3 -TiO 2 ) exhibits much higher activities than the corresponding nanoparticle catalyst (Pt NP /WO 3 -TiO 2 ) in photo-thermo catalytic oxidation of C 3 H 8 and C 3 H 6 , which represent different kinds of typical VOCs. A key finding is that the activities of Pt 1 /WO 3 -TiO 2 and Pt NP /WO 3 -TiO 2 can be accelerated in photo-thermo catalytic C 3 H 8 oxidation by overcoming oxygen poisoning. Upon the light irradiation, the apparent active energy ( E a ) of the Pt 1 /WO 3 -TiO 2 and Pt NP /WO 3 -TiO 2 decline from 116 to 60 kJ·mol −1 and from 103 to 30 kJ·mol −1 , respectively, substantiating their effectiveness in photo-thermo catalysis. Notably, a substantially higher reaction rate of 3792 μmol∙g Pt −1 ∙s −1 on the Pt 1 /WO 3 -TiO 2 is achieved, which should be a benchmark for C 3 H 8 oxidation. More intriguingly, photo-thermo catalytic C 3 H 6 oxidation on the Pt NP /WO 3 -TiO 2 is prohibited due to the strong adsorption-induced C 3 H 6 poisoning on the Pt nanoparticles, for which the E a of the Pt NP /WO 3 -TiO 2 catalyst for C 3 H 6 oxidation is maintained at approximately 55 kJ·mol −1 , regardless of the light irradiation. In comparison, the C 3 H 6 poisoning on the Pt 1 /WO 3 -TiO 2 can be mitigated by light illumination, where the E a of the Pt 1 /WO 3 -TiO 2 catalyst for C 3 H 6 oxidation dramatically reduced from 49 to 16 kJ·mol −1 , signifying that the high energy barrier of C 3 H 6 oxidation can be mediated by the light. Profiting from the apt affinity between C 3 H 6 and Pt single atoms, the photogenerated electrons accumulated on the Pt single atoms produce repulsive force towards the electron-rich C 3 H 6 molecules, which is conducive to the C 3 H 6 desorption from the Pt 1 /WO 3 -TiO 2 . Therefore, the Pt 1 /WO 3 -TiO 2 exhibits enhanced activity in photo-thermo catalytic C 3 H 6 oxidation. This study exemplifies that the advantages of SAC are not only saving the consumption of precious metals but also discovering new catalytic reactions on the account of the specific electronic characteristic. Download: Download high-res image (85KB) Download: Download full-size image
研究领域:
催化化学
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环境科学
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材料科学
✓ 已验证
DOI
高影响因子
Nanoscale Research Letters
·
2020
·Vol. 15
·期 1
·1-15
·
IF 3.578
Fan Li,Sun Qi,Zheng Wei,Tang Qinyuan,Zhang Ting,Tian Mengkui
The rutile Sn x Ti 1− x O 2 ( x = 0, 0.33, 0.5, 0.67, 1) solid solution was synthesized by a one-step hydrothermal method, in which tetrabutyl titanate and Tin (IV) chloride pentahydrate were used as raw materials. A series of Ru/Sn x Ti 1− x O 2 were then prepared by the impregnation process in RuCl 3 to investigate the performance and stability of CO and C 3 H 8 oxidation. These catalysts were characterized through XRD, N 2 adsorption-desorption, FT-IR, TEM, XPS, H 2 -TPR, and O 2 -TPD techniques. The effect of Sn/Ti molar ratio and hydrothermal condition on the low-temperature catalytic oxidized performance and stability of Ru/Sn x Ti 1− x O 2 were investigated. The results indicated that Ru/Sn 0.67 Ti 0.33 O 2 catalyst showed an excellent activity and stability at low temperatures. The CO conversion reached 50% at 180 °C and 90% at 240 °C. Besides, the C 3 H 8 conversion reached 50% at 320 °C, the complete conversion of C 3 H 8 realized at 500 °C, and no deactivation occurs after 12 h of catalytic reaction. The excellent low-temperature activity and stability of the Ru/Sn 0.67 Ti 0.33 O 2 were attributed to the following factors. Firstly, XRD results showed that Sn 4+ was successfully introduced into the lattice of TiO 2 to replace Ti 4+ forming a homogeneous solid solution (containing –Sn 4+ –O–Ti 4+ – species), which was consistent with TEM and N 2 adsorption-desorption results. The introduction of Sn could suppress the growth of anatase crystal and promote the formation of rutile phase, and this phase transition was helpful to improve the low-temperature activity of the catalysts. Secondly, TEM images showed that ultrafine Ru nanoparticles (~ 5 nm) were dispersed on Sn 0.67 Ti 0.33 O 2 support, suggesting that the formation of Sn x Ti 1− x O 2 solid solution was beneficial to the dispersion of Ru particles.
研究领域:
催化化学
·
材料科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Catalysis Science & Technology
·
2024
·
IF 4.4
Yumeng Xu,Rongzhou Chen,Hailian Tang,Lu Yan,Fei Huang,Ming Tian,Kaibao Wu,Yanliang Zhou,Jian Lin,Ying Zheng,Xiaodong Wang
Promoting the thermal stability of supported noble metal catalysts under harsh conditions remains challenging for the modern chemistry industry. Herein, Fe-substituted hexaaluminate supported Pt catalysts (Pt/BaFeAl11O19) were synthesized and treated with high temperature at 800 °C under different atmospheres. The Pt particles showed severe sintering under an oxidative atmosphere but high stability under reductive conditions. Interestingly, Pt/BaFeAl11O19 pre-reduced at high temperature possessed improved anti-sintering ablility during oxidative annealing. The characterization results demonstrate that oxygen vacancies were facilely formed under an H2 atmosphere to favor the formation of coating layers on Pt nanoparticles. This structure helps retain oxygen vacancies during subsequent oxidative calcination, contributing to promoted stability. The high thermal stability of Pt particles coupled with the easy generation of Fe2+ sites in Pt/BaFeAl11O19 resulted in excellent catalytic performance for CO and C3H8 oxidation after cycling hydrothermal aging at 800 °C.
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
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