Article
Nanoscience & Nanotechnology
Young Jin Sa, Sohee Kim, Yesol Lee, Ji Man Kim, Sang Hoon Joo
Summary: In this study, four different mesoporous manganese oxides were synthesized and used as model catalysts to investigate the effects of local structures and Mn valence states on the activity of oxygen electrocatalysis. The results showed that for the oxygen reduction reaction, m-Mn2O3 exhibited the highest activity, followed by m-MnO2, m-MnO, and m-Mn3O4. For the oxygen evolution reaction, m-MnO2 showed the highest activity, followed by m-Mn2O3, while m-MnO and m-Mn3O4 had lower activity. These findings suggest that high-valent Mn species and disordered atomic arrangements induced by nanostructuring significantly affect electrocatalysis.
ACS APPLIED MATERIALS & INTERFACES
(2023)
Article
Chemistry, Multidisciplinary
Tomas R. Reina, Miriam Gonzalez-Castano, Victor Lopez-Flores, L. T. Marcela Martinez, Andrea Zitolo, Svetlana Ivanova, Wenquian Xu, Miguel Angel Centeno, Jose A. Rodriguez, Jose Antonio Odriozola
Summary: In this study, it was demonstrated using in situ X-ray absorption spectroscopy that both Au and Pt remain unoxidized during the water-gas shift (WGS) reaction, with significant differences in their dynamics under WGS atmospheres. While Pt undergoes restructuring into metallic particles, Au nanoparticles experience particle splitting and agglomeration processes, maintaining a zero oxidation state throughout the reaction.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2022)
Article
Chemistry, Physical
Hailing Yi, Yanhao Wang, Lingling Diao, Yanjun Xin, Chao Chai, Dejie Cui, Dong Ma
Summary: Ultrasonic treatment was applied to α-MnO2 to fabricate a new u-α-MnO2 catalyst for PMS activation, which showed improved catalytic performance due to alterations in crystalline and pore structures, formation of defects, and higher contents of trivalent Mn and oxygen vacancies on the catalyst surface.
JOURNAL OF COLLOID AND INTERFACE SCIENCE
(2022)
Article
Chemistry, Physical
Min Li, Hao Zhang, Zhiliang Liu, Yiguo Su, Chunfang Du
Summary: Manganese-based heterostructure catalysts with active interfaces and oxygen vacancies were successfully synthesized and showed excellent catalytic activity in the degradation of Bisphenol A. The presence of disordered interfaces, higher content of oxygen vacancies, and closer ratio of Mn(IV) to Mn(II) contributed to the enhanced catalytic performance. This study provides new insights for constructing heterostructures and offers a promising catalyst for pollutants removal.
APPLIED SURFACE SCIENCE
(2023)
Article
Chemistry, Physical
Aigerim Galyamova, Hyunwoo Ha, Graeme Henkelman, Richard M. Crooks
Summary: In this article, a robust experimental model investigating strong metal-support interactions (SMSI) and their impact on electrocatalytic reactions is reported. The beneficial interactions between Ni0.9O thin film supports and PtNPs in the CO electrooxidation reaction are described. The results show negative shifts of the CO electrooxidation peak potential when Ni0.9O thin films are in contact with Pt55 NPs and Pt140 NPs, and the oxygen evolution reaction (OER) is suppressed only when PtNPs are in contact with Ni0.9O thin films. Density functional theory (DFT) calculations attribute the CO electrooxidation enhancement and OER suppression to changes in binding energies at the NiO(111)/Pt55 NP interface.
JOURNAL OF PHYSICAL CHEMISTRY C
(2023)
Article
Energy & Fuels
Menna M. Hasan, Aya K. Gomaa, Ghada E. Khedr, Kholoud E. Salem, Basamat S. Shaheen, Nageh K. Allam
Summary: The demand for green and sustainable energy sources has increased in recent years. This study focuses on identifying nonprecious and cheap electrocatalysts for water splitting. Nanosheets of different earth-abundant elements were electrodeposited on commercial Ti mesh and tested for water splitting. The catalysts showed higher catalytic activity after phosphidation treatment. The study provides insights into the performance and optimization of the catalysts.
Article
Engineering, Environmental
Dongning Wei, Jing Liu, Zirui Luo, Xiande Xie
Summary: The oxidation rates and adsorption capacity of antimonite (Sb (III)) on six different structures of manganese oxides (MnxOy) were investigated. Higher reduction potential and specific surface area favored faster Sb(III) oxidation, while Mn(III) and oxygen vacancies exhibited a synergistic effect on Sb(III) oxidation. The results provide mechanistic insight into the fate of Sb(III) in Mn-rich environments.
Article
Chemistry, Physical
Rui Huang, Li Luo, Wei Hu, Zhixin Tang, Xing Ji, Leqi Chen, Zhaoshi Yu, Yunhuai Zhang, Dan Zhang, Peng Xiao
Summary: Studies have shown that adjusting the pH value of redox precipitation during the synthesis of Co-Mn catalysts can optimize the surface structure of the catalyst, improving its catalytic performance and stability in toluene oxidation. The Co-Mn-12 catalyst synthesized at pH = 12 exhibits the best catalytic activity and water-resistance.
CATALYSIS SCIENCE & TECHNOLOGY
(2022)
Article
Chemistry, Multidisciplinary
Tzu-Hao Lu, Chenghui Zeng, Haozhe Zhang, Xin Shi, Yanxia Yu, Xihong Lu
Summary: A oxygen defects-rich manganese oxide (MnO2-x) is reported as a host material for ammonium ions (NH4+) storage, which exhibits improved electric conductivity and low interface activation energy due to the oxygen defects. The electrochemical reaction mechanism is confirmed through ex situ XPS and FT-IR, demonstrating the insertion and extraction of NH4+ in MnO2-x via hydrogen bond formation/breaking. As a result, MnO2-x delivers a high capacity of 109.9 mAh g(-1) at 0.5 A g(-1) current density and retains 24 mAh g(-1) after 1000 cycles at 4 A g(-1) current density, outperforming the pristine MnO2 sample.
Article
Chemistry, Physical
Jongsik Kim, Seokhyun Lee, Heon Phil Ha
Summary: The study demonstrated that supercritical CO2 extraction can adjust the quantities/strengths of surface sites on Mn oxide, improving the selectivities to desired N-2 and promoting SO2 tolerance. The mechanism involves promoting unique NOx reduction pathways to produce N-2 only while detouring undesired byproducts, and tailoring redox sites to deter NH3 oxidation. Additionally, Mn-CO2 showed enhanced long-term stability in reducing NOx over Mn in the presence of SO2 at lower temperatures, providing higher selectivities to desired N-2.
Article
Chemistry, Multidisciplinary
Xin Xing, Ting Zhao, Jie Cheng, Xiaoxiao Duan, Wenpeng Li, Ganggang Li, Zhongshen Zhang, Zhengping Hao
Summary: This study investigates a series of Cu-promoted Ce-Zr mixed oxide catalysts for the catalytic elimination of nitrogen-containing volatile organic compounds (NVOCs). Among them, the CeCu10%ZrOx catalyst exhibits the best catalytic performance, achieving 100% n-butylamine conversion and 90% N-2 selectivity, as well as good water resistance. The catalyst was characterized through experimental studies and theoretical calculations, and the reaction mechanism was explored. The findings highlight the potential application of this catalyst in the selective oxidation of n-butylamine.
CHINESE CHEMICAL LETTERS
(2022)
Article
Engineering, Environmental
Yanzhi Li, Shi Liu, Kehan Yin, Dongyan Jia, Yundong Sun, Xueying Zhang, Jingchun Yan, Li Yang
Summary: The ABO(3)-type perovskite oxides have the advantages of being able to tailor the redox capability of transition metal elements in their lattice structure through a simple doping strategy, making them an ideal platform for catalytic combustion of VOCs. This study synthesized and analyzed a series of La1-xSrxCo1-yFeyO3 perovskites for toluene combustion. Among the catalysts, La0.5Sr0.5Co0.8Fe0.2O3-delta (LSCF) showed remarkable activity for toluene oxidation and exhibited superior stability. The outstanding catalytic activity of LSCF perovskite is attributed to the enhancement of redox ability, generation of oxygen vacancies, and activation of lattice oxygen species.
JOURNAL OF ENVIRONMENTAL CHEMICAL ENGINEERING
(2023)
Article
Chemistry, Physical
Chih-Huang Weng, Chong-Yi Liao, Jing-Hua Tzeng, Ying-Chen Chen, Jin Anotai, Yao-Tung Lin
Summary: Developing oxygen vacancies in nanomaterials is an effective method to enhance catalytic performance. In this study, a novel low-cost ternary iron-manganese-copper mixed oxide catalyst with abundant oxygen vacancies was successfully synthesized. Characterization analyses revealed the metal valence transformation, synergy structure, and role of oxygen vacancies in the catalyst, demonstrating its excellent catalytic oxidation performance. The stable and active structure of the catalyst after oxidizing ethylene suggests a redox cycle of catalytic mechanism. This work provides valuable insights into the development of high-performance and stable catalysts with abundant oxygen vacancies for VOCs elimination.
APPLIED SURFACE SCIENCE
(2023)
Article
Chemistry, Physical
Wei Chen, Jue Xu, Fajun Huang, Chaoying Zhao, Yingqiao Guan, Yarong Fang, Jinpeng Hu, Weiwei Yang, Zhu Luo, Yanbing Guo
Summary: In this study, TiO2-supported copper catalysts (CuOx/TiO2) with different ratio of oxygen vacancies (Ov) and Cu+ were synthesized, and the existence and amount of Ov and Cu+ species were characterized. The synergetic effect between Cu+ and oxygen vacancies was investigated, and Cu+ was found to be the adsorption site for CO molecules, while abundant Ov could effectively activate molecular oxygen to oxidize CO. The most suitable ratio between Cu+ and Ov was confirmed, and CuOx/TiO2 (Cu+ rich) catalyst exhibited superior CO oxidation activity compared to CuOx/TiO2 (Ov rich) catalyst.
APPLIED SURFACE SCIENCE
(2023)
Article
Energy & Fuels
Xuxu Zhai, Luming Li, Shuang Song, Junjun Zhang, Jun Ma, Chongrui Xie, Wei Chu
Summary: A series of MnO2 catalysts with different crystal forms were successfully synthesized by inducing self-doping of Mn through bridging interaction with carboxyl group. Among them, the dual crystal structure catalyst, MnCA-4, demonstrated the best catalytic performance in toluene oxidation, attributed to the interaction between different crystal structures. The study also revealed that MnCA-4 catalyst had stronger adsorption and activation abilities towards toluene.
Article
Chemistry, Applied
Xiang Gao, Yajun Zhou, Lixiu Feng, Feixiang Tian, Xiaohui Liu, Jing Xu, Yongsheng Li
MICROPOROUS AND MESOPOROUS MATERIALS
(2019)
Article
Chemistry, Multidisciplinary
Liuqingqing Yang, Laura Pastor-Perez, Juan Jose Villora-Pico, Antonio Sepulveda-Escribano, Feixiang Tian, Minghui Zhu, Yi-Fan Han, Tomas Ramirez Reina
Summary: The study demonstrates that bimetallic Fe-Cu catalysts show a remarkable enhancement in catalytic performance compared to monometallic systems for the RWGS reaction, especially at low temperatures. The optimal Fe/Cu oxides mass ratio of 0.25/0.75 exhibits commendable CO2 conversion levels and selectivity. Copper species on the catalytic surface interact with multioxide phases like Fe3O4/CeO2, enhancing catalytic activity.
ACS SUSTAINABLE CHEMISTRY & ENGINEERING
(2021)
Article
Nanoscience & Nanotechnology
Fei-Xiang Tian, Hu Li, Minghui Zhu, Weifeng Tu, Dehai Lin, Yi-Fan Han
Summary: Different MnO2 polymorphs were studied for their properties in CO oxidation, with beta-MnO2 showing higher activity and stability. The mechanism of CO oxidation over MnO2 was proposed based on in situ spectra and intrinsic kinetic studies.
ACS APPLIED MATERIALS & INTERFACES
(2022)
Review
Chemistry, Multidisciplinary
Yuan Gao, Mingxin Jiang, Liuqingqing Yang, Zhuo Li, Fei-Xiang Tian, Yulian He
Summary: Methane plays an important role in carbon neutrality but its increasing atmospheric concentration poses a threat to global temperature. Catalytic methane combustion is an effective strategy to address this issue, with transition metal oxide catalysts attracting attention as alternatives to noble-metal-based catalysts. This review summarizes the recent research advances in transition metal oxide-based catalytic methane combustion reactions, including the reaction mechanisms and properties of these catalysts.
FRONTIERS IN CHEMISTRY
(2022)
Article
Chemistry, Physical
Hu Li, Fei-Xiang Tian, Qi Liu, Yi-Fan Han, Minghui Zhu
Summary: Copper-cerium catalysts are commonly used for the oxidation of CO. This study prepared CuO/CeInOx catalysts and found that the inclusion of In dopants improved the catalyst's activity. The Cu/Ce90In10Ox catalyst showed excellent CO oxidation activity at low temperatures.
CATALYSIS SCIENCE & TECHNOLOGY
(2022)
Article
Chemistry, Physical
Yifan Sun, Ye Lv, Wei Li, Jinli Zhang, Yan Fu
Summary: In this study, PtRu electrocatalysts were fabricated on carbon paper via cyclic electrodeposition for the electrocatalytic hydrogenation (ECH) of phenol. The Pt3Ru3 catalyst exhibited excellent activity and stability for the conversion of phenol to cyclohexanol at ambient temperature and various current densities. The in situ Raman spectroscopy and kinetic study revealed the hydrogenation mechanism of phenol over Pt3Ru3 in acidic electrolyte, providing an effective electrochemical strategy for the facile construction of durable electrode materials and efficient phenol hydrogenation.
JOURNAL OF CATALYSIS
(2024)
Article
Chemistry, Physical
Amir Shahzad, Khezina Rafiq, Muhammad Zeeshan Abid, Naseem Ahmad Khan, Syed Shoaib Ahmad Shah, Raed H. Althomali, Abdul Rauf, Ejaz Hussain
Summary: Photocatalytic hydrogen production through water splitting is an effective method for meeting future energy demands. In this study, researchers synthesized a 1 % Ag2S/Cu2S co-doped CdZnS catalyst and found that it can produce hydrogen at a higher rate. The co-doping of Ag2S and Cu2S in the CdZnS catalyst showed a synergistic effect, with Ag2S promoting oxidation reactions and Cu2S promoting reduction reactions.
JOURNAL OF CATALYSIS
(2024)
