Article
Chemistry, Physical
Pengfei Li, Tiezhen Zhang, Haixiao Sun, Yufeng Gao, Yanyuan Zhang, Yuanyuan Liu, Chengmin Ge, Hao Chen, Xiaoping Dai, Xin Zhang
Summary: This study reports the fabrication of a cobalt-doped trimetallic catalyst through pyrolysis of a metal-organic framework, which shows excellent performance in NH3 selective catalytic reduction, high water and sulfur resistance, and good stability. The results suggest the potential for developing a high stability catalyst for low-temperature selective catalytic reduction of NOx with NH3.
Article
Chemistry, Physical
Xusheng Ren, Zhiliang Ou, Bang Wu
Summary: The study demonstrates the potential of activated coke-supported Mn-Cu catalysts for NOx removal, with 8 wt.% Mn0.7Cu0.3/AC showing the best catalytic activity at 200 degrees C. The deactivation caused by SO2 can be reversed by water washing regeneration, which restores the activity-related values to the level of fresh catalysts. These findings provide valuable insights for the design and development of SCR catalysts.
Article
Engineering, Environmental
Minkyu Jeon, Eunsong Lee, Minsu Kim, Hyunwook Jegal, Sangbin Park, Jun Hwa Chi, Sehyun Baek, Jongmin Lee, Sang-In Keel
Summary: Researchers investigated the emission levels of NO and N2O from existing coal-fired power plants and future carbon-neutral coal/ammonia co-fired power plants. They found a correlation between NO and N2O gases generated during combustion, and analyzed the emissions during the SNCR and SCR processes of NOx. They also observed a linear correlation between CO and N2O concentrations. The findings of this study can help control the emission levels of air pollutant NO and greenhouse gas N2O in thermal power plants.
JOURNAL OF ENVIRONMENTAL CHEMICAL ENGINEERING
(2023)
Article
Chemistry, Applied
Kyung-yo Park, Bora Ye, Myeung-jin Lee, Geumyeon Lee, Bora Jeong, Donghyuk Kim, Jae-il Jung, Han-gyu Im, Heesoo Lee, Hong-Dae Kim
Summary: Selective catalytic oxidation (SCO) is an effective method to reduce CO and NH3 emissions. In this study, WS2 was added to Pt/TiO2 catalyst to synthesize a catalyst that is not easily poisoned by SO2 and shows improved oxidation performance.
Article
Thermodynamics
Jun Li, Binxuan Zhou, Jingcai Chang, Qingbai Tian, Chunyuan Ma, Liqiang Zhang, Tao Wang, Shouyan Chen, Guifang Chen, Zhanlong Song
Summary: This study focuses on the innovative preparation of elemental sulfur from saturated activated coke (SAC) by one-step thermal regeneration coupled with SO2 carbothermal reduction. The experimental results showed that a rapid rise in temperature in SAC caused rapid SO2 desorption, resulting in a larger instantaneous SO2 concentration and smaller carbon loss. At temperatures higher than 550 degrees C, most of the adsorbed sulfur converted into gaseous SO2, and a small amount was converted into elemental sulfur with a selectivity of 3.69%. In the temperature range of 650-950 degrees C, the rapid desorption of SO2 coupled with carbothermal reduction improved the selectivity of elemental sulfur and achieved a near-complete conversion at 950 degrees C of 93.7%. Furthermore, the re-absorption performance of regenerated AC at 750 degrees C reached the maximum value of 67.27 mg/g and approached the original AC value of 66.44 mg/g.
Article
Engineering, Environmental
Qiulin Wang, Rui Wang, Xiaoniu Huang, Huancong Shi
Summary: This paper investigates the resistance of MnOx-CeO2/TiO2 catalyst to SO2 and H2O, and discusses their poisoning mechanism based on catalytic characterizations. The results show that the catalyst exhibits high tolerance to SO2 poisoning due to the preferential formation of surface sulfates on Ce dopants, which protect the main active component. However, the presence of both SO2 and H2O leads to more severe catalytic deactivation, indicating their synergistic toxicity in poisoning the catalyst.
JOURNAL OF ENVIRONMENTAL CHEMICAL ENGINEERING
(2022)
Article
Chemistry, Physical
Beilong Lin, Jiawei Zhang, Haifeng Shi, Ziying Chen, Boqiong Jiang
Summary: The adsorption amount of C3H6 on Cu-Mn/SAPO-34 was lower compared to Cu-Mn/ZSM-5, but it could maintain more hydroxyl groups to form intermediates in the SCR reaction, resulting in a higher resistance.
CATALYSIS SCIENCE & TECHNOLOGY
(2021)
Article
Chemistry, Multidisciplinary
Jianbin Luo, Hongxiang Xu, Xiguang Liang, Shizhuo Wu, Zhonghang Liu, Yuanhao Tie, Mingsen Li, Dayong Yang
Summary: Selective catalytic reduction (SCR) system is considered the most effective control method for reducing NOx in diesel engine exhaust gas. Catalysts play a key role in the de-NOx efficiency of SCR reactions. This paper reviews the recent progress in low-temperature NH3-SCR catalysts using copper zeolite catalysts and discusses the challenges and potential solutions. The summary and future research direction of copper zeolite catalysts for low-temperature SCR are also presented.
RESEARCH ON CHEMICAL INTERMEDIATES
(2023)
Article
Engineering, Environmental
Xueke Shi, Jiaxiu Guo, Ting Shen, Aidong Fan, Shandong Yuan, Jianjun Li
Summary: Cerium modified La-Mn oxides show high NOx conversion rates and N2 selectivity in NH3-SCR reaction, with good resistance to SO2 and H2O. Ce doping optimizes the structure of La-Mn oxides, allowing them to maintain their perovskite structure while some CeOx and Mn3O4 leak out.
CHEMICAL ENGINEERING JOURNAL
(2021)
Article
Engineering, Chemical
Erez B. Ruck, Oren Ben Porat, Youri Gendel
Summary: A new two-step technique was developed for selectively separating chloride ions from acidic aqueous solutions. The process operates at ambient temperature and pressure, and is powered by H2 gas and atmospheric oxygen. The Pt-Ag-AC catalyst composed of activated carbon loaded with platinum nano size crystals and metallic silver particles, enables the oxidation of Ag0 to Ag+ and the subsequent formation of insoluble AgCl precipitate on the catalyst through the aeration of acidic chloride solution. The regeneration of the Pt-AgCl-AC is achieved through hydrogenation, leading to the reduction of AgCl into Ag0 and the release of Cl- ions.
SEPARATION AND PURIFICATION TECHNOLOGY
(2023)
Article
Nanoscience & Nanotechnology
Pengye Zhang, Jundie Hu, Yangbin Shen, Xiaogang Yang, Jiafu Qu, Feng Du, Wei Sun, Chang Ming Li
Summary: By combining light with enzymes, a metal-free heterojunction of pyromellitic diimide/g-C3N4 (PDI/CN) with excellent visible light response was fabricated for efficient conversion of CO2 to formic acid. The unique photoenzymatic catalytic cascade system and heterointerface effect of PDI/CN contributed to the high selectivity and yield achieved. This work provides an efficient strategy and photocatalyst for the directional conversion of CO2 to formic acid.
ACS APPLIED MATERIALS & INTERFACES
(2021)
Article
Green & Sustainable Science & Technology
Jiang Deng, Sha Wang, Tianwei Lan, Shiqi Guo, Kai Zhang, Dengsong Zhang
Summary: The use of catalysts is crucial for reducing emissions and improving sustainability in industrial processes. However, the poisoning of catalysts by alkali and heavy metals can limit their effectiveness and increase environmental impacts. This study proposes a precise regeneration approach for metal-poisoned catalysts, using the Sabatier principle and formic acid, which showed high removal efficiency for metal poisons and retention of active species. This approach not only extends the catalysts' lifetime, but also reduces the environmental impact of spent catalyst disposal.
JOURNAL OF CLEANER PRODUCTION
(2023)
Article
Energy & Fuels
Bolin Zhang, Lifeng Deng, Michael Liebau, Peiqiang Wang, Yingjie Ren, Bo Liu, Chunyun Luo, Roger Glaser, Shengen Zhang
Summary: This study successfully removed the tar species on the catalyst's surface and restored the catalyst's activity through an effective pyrolysis method. The optimized pyrolysis treatment maintained the mechanical properties of the catalyst at a high level and achieved efficient NO conversion and N-2 selectivity at a relatively low temperature range.
Article
Biotechnology & Applied Microbiology
Quanming Liang, Jian Li, Tao Yue
Summary: The addition of 3% CeO2 improved the performance and resistance of the V2O5-WO3/TiO2 catalyst by establishing a protective layer. The experiment showed that layered filling can slow down the catalyst's deactivation rate, and the deposition amounts of NH4+ and SO42- can be used as indicators for judging the degree of poisoning.
ENVIRONMENTAL TECHNOLOGY & INNOVATION
(2021)
Review
Chemistry, Applied
Jongsik Kim, Somin Lee, Dong Wook Kwon, Heon Phil Ha
Summary: Rare earth metal vanadates have shown promise for converting NOX to N-2 at high temperatures, but face limitations in catalytic activity due to weak hydrothermal stability, low N-2 selectivity, and limited active sites. This study demonstrates the efficacy of structurally modifying vanadate with additional rare earth metals to generate bimetallic vanadates with improved reactivity and stability.
Article
Chemistry, Applied
Jingjing Liu, Yanlong Huo, Xiaoyan Shi, Zhongqi Liu, Yulong Shan, Yunbo Yu, Wenpo Shan, Hong He
Summary: A series of Ce-Sn catalysts modified with W were prepared and studied for the SCR of NOx by NH3. The Ce-W-Sn catalysts showed higher deNOx efficiency than the Ce-Sn catalysts, and the Ce1W0.24Sn2Ox catalyst prepared by coprecipitation displayed the highest NOx conversion. The mechanism by which W modification improved the structure and function of the Ce1Sn2Oy catalyst was investigated, revealing the promotion of t-Sn(Ce)O2 active phase formation and the inhibition of c-Ce(Sn)O2 phase generation by W species. Additionally, the highly dispersed W species on the Ce1W0.24Sn2Ox catalyst surface formed new Ce-O-W active sites, contributing to enhanced NH3-SCR performance and the suppression of excess NH3 oxidation.
Article
Chemistry, Physical
Zhi Liu, Guangyan Xu, Lingyou Zeng, Wei Shi, Yingjie Wang, Yanwei Sun, Yunbo Yu, Hong He
Summary: We prepared a PtPd-La1/Al2O3 catalyst with highly dispersed La species and Pt-PdO nanoparticles, showing significantly enhanced hydrothermal and long-term stability under the harsh conditions of simulated natural gas vehicle (NGV) exhaust. PdO nanoparticles can be anchored by highly dispersed La sites through electron transfer, inhibiting the sintering of Pd species during hydrothermal aging. Pt uniformly doped in PdO creates high-efficiency Pt sites and unsaturated Pd sites for water-resistance, further enhancing long-term stability. This work provides the potential to resolve tough challenges related to methane emission control on NGVs.
APPLIED CATALYSIS B-ENVIRONMENTAL
(2023)
Article
Chemistry, Physical
Jingjing Liu, Xiaoyan Shi, Yunbo Yu, Mengyuan Zhang, Diru Liu, Hong He
Summary: The HC resistance of CeWSnOx, V2O5-WO3/TiO2, and Cu-SSZ-13 catalysts was studied using propene, toluene, and n-pentane as model HCs. The CeWSnOx catalyst showed much better HC tolerance due to its strong HC oxidation capacity, which inhibited side reactions. In contrast, Cu-SSZ-13 and V2O5-WO3/TiO2 showed undesired HC ammoxidation reactions, especially in the presence of propene.
APPLIED CATALYSIS B-ENVIRONMENTAL
(2023)
Article
Chemistry, Physical
Qiaoqi Guo, Ying Luo, Jun Xu, Lidan Deng, Zheng Wang, Hong He
Summary: Photocatalytic conversion of low-concentration CO2 with H2O oxidation is an effective method to achieve sustainable carbon cycling and address the global warming issue. Improving charge separation, surface adsorption, and catalytic process of photocatalysts is crucial to overcome the mass transfer limitation during the conversion of low-concentration CO2. In this study, a highly-crystalline AgxNa1_xTaO3-AgCl heterostructure composite was fabricated, which facilitated the separation and transfer of photogenerated charges. The introduction of Ag cations and AgCl components enhanced the adsorption and activation of CO2 on the surface of the photocatalyst. When combined with metallic Ag cocatalysts, the AgxNa1_xTaO3-AgCl heterostructure photocatalyst exhibited improved activity for CO2 reduction and H2O oxidation at low CO2 concentration conditions. The development of photocatalysts active at low CO2 concentration provides an alternative approach for practical CO2 conversion systems in the future.
APPLIED CATALYSIS B-ENVIRONMENTAL
(2023)
Article
Engineering, Environmental
Meng Gao, Zhuocan Li, Guangzhi He, Yulong Shan, Yu Sun, Hong He
Summary: This study reveals the origin of the distinct difference in selectivity of oxide catalysts in the NH3-SCR reaction. By combining experimental measurements and density functional theory calculations, the researchers demonstrate that the selectivity difference is determined by the gap in the energy barriers between N2 formation and N2O formation from the consumption of the key intermediate NH2NO. This work provides fundamental insights into the origin of selectivity in the selective catalytic reduction of NO.
ENVIRONMENTAL SCIENCE & TECHNOLOGY
(2023)
Article
Engineering, Environmental
Junlin Chen, Yulong Shan, Yu Sun, Wenqing Ding, Sen Xue, Xuewang Han, Jinpeng Du, Zidi Yan, Yunbo Yu, Hong He
Summary: This study investigated the effects of phosphorus on Cu-SSZ-39 catalysts before and after hydrothermal aging treatment. Phosphorus poisoning significantly decreased the low-temperature NH3-SCR catalytic activity, but this activity loss was alleviated by further hydrothermal aging treatment. Characterization techniques revealed that Cu-P species produced by phosphorus poisoning decreased the redox ability of active copper species, resulting in the observed low-temperature deactivation. However, after hydrothermal aging treatment, Cu-P species partly decomposed, leading to the recovery of low-temperature NH3-SCR catalytic activity.
ENVIRONMENTAL SCIENCE & TECHNOLOGY
(2023)
Article
Engineering, Environmental
Maofan Li, Meng Gao, Guangzhi He, Yunbo Yu, Hong He
Summary: Mn doping can significantly enhance the low-temperature NH3-SCR activity of Ce-based oxide catalysts, providing important insights for the development of low-temperature Ce-based catalysts.
ENVIRONMENTAL SCIENCE & TECHNOLOGY
(2023)
Article
Geosciences, Multidisciplinary
Yanmin Dong, Hongkai Li, Shengzhong Wang, Hongshi He
Summary: This study examines the relationship between peatland development, lateral expansion, and carbon accumulation rate with climate and local conditions in the Baijianghe peatland. The results show that climate and local conditions have an important influence on carbon accumulation rates in the peatland.
SCIENCE CHINA-EARTH SCIENCES
(2023)
Article
Soil Science
Na Li, Haibo Du, Mai-He Li, Risu Na, Renkai Dong, Hong S. He, Shengwei Zong, Lirong Huang, Zhengfang Wu
Summary: Global environmental changes have led to the migration of plants into alpine or arctic tundra ecosystems. In the Changbai Mountain, the migration of the low-elevation herb species Deyeuxia angustifolia into the alpine shrubby tundra has resulted in changes in soil properties and soil microbial communities. The upward migration, combined with nitrogen deposition, has altered the soil microbial community composition and led to a shortage of soil phosphorus at higher elevations. These changes may benefit the migration of D. angustifolia and suppress the existing shrubby species.
SOIL BIOLOGY & BIOCHEMISTRY
(2023)
Article
Chemistry, Physical
Qi An, Guangyan Xu, Jianhua Liu, Yingjie Wang, Yunbo Yu, Hong He
Summary: In this study, a bifunctional Pt/Cu-SSZ-13 catalyst with catalytic selectivity and selective catalytic reduction function was successfully prepared. The catalyst exhibited excellent catalytic performance during NH3 oxidation under practical conditions containing water vapor, achieving >85% N2 selectivity over the whole temperature range.
Article
Thermodynamics
Hong He, Yu Xing, Runguo Wang, Yonglai Lu, Liqun Zhang, Fanzhu Li
Summary: Non-pneumatic tires are targeted for their puncture resistance and low-energy consumption. This study proposes a new idea for conformal cooling layout in non-pneumatic tire molding molds and establishes a three-dimensional model for optimizing the cooling system. Through simulation and experiment, a semi-annular conformal cooling channel layout with significant improvements in pressure loss, cycle time, cooling time, and tire shrinkage rate is found. This optimized design can shorten production cycles, increase efficiency, reduce energy loss, and improve tire quality.
THERMAL SCIENCE AND ENGINEERING PROGRESS
(2023)
Review
Multidisciplinary Sciences
Yuan Liu, Guangzhi He, Biwu Chu, Qingxin Ma, Hong He
Summary: Soot particles, consisting of elemental carbon and organic compounds, have significant impacts on climate, the environment, and human health. They are chemically and physically active in atmospheric aging processes, leading to changes in composition, morphology, hygroscopicity, and optical properties. The interactions between soot and atmospheric substances, as well as the heterogeneous reactions on soot, have been extensively studied to better understand the environmental behaviors of soot.
FUNDAMENTAL RESEARCH
(2023)
Article
Chemistry, Physical
Hui Zhang, Zhihua Lian, Chunxi Lin, Ying Zhu, Wenpo Shan, Hong He
Summary: This study investigates the improvement of low-temperature activity and SO2 durability of ceria-based catalysts by Fe doping. The enhanced low-temperature activity is attributed to the improved redox properties, more active oxygen species, and enhanced adsorption and activation of NOx species. Fe doping also prevents sulfate deposition and alters the competitive adsorption behavior between NO and SO2, leading to excellent sulfur resistance.
JOURNAL OF COLLOID AND INTERFACE SCIENCE
(2023)
Article
Meteorology & Atmospheric Sciences
Yuanyuan Fu, Chang Liu, Hong He, Shaoqiang Wang, Lunche Wang, Zhijie Xie
Summary: Exploring spring phenology dynamics in the Greater Khingan Mountains, Northeast China, we found that preseason temperature strongly influenced the start of the growing season (SOS), while the effects of preseason precipitation and radiation varied by region. The SOS dates showed regional characteristics, with a gradual delay from north to south.
INTERNATIONAL JOURNAL OF CLIMATOLOGY
(2023)
Article
Engineering, Environmental
Zhi Liu, Yingsheng An, Guangyan Xu, Yunbo Yu, Hong He
Summary: The mechanistic cause of the enhancement of the C3H6-SCR activity of Ag/Al2O3 by trace Pd doping and the corresponding structure-property relationship were investigated. Pd doping enhanced the water resistance of Ag/Al2O3 for C3H6-SCR by changing the reaction pathway. Under wet conditions, a series of in situ DRIFT studies indicated that the production of an active acetate intermediate on Ag/Al2O3 was suppressed during the partial oxidation of C3H6, while trace Pd doping promoted the formation of another active intermediate, an enolic species. Furthermore, a pathway for the formation of enolic species by the reaction of acrylate with hydroxyl species was proposed. DFT calculations revealed that the surface of Ag clusters was easily covered by hydroxyl in the presence of water vapor, which could inhibit the formation of acetates. Doping with Pd facilitated the activation of acrylate which might further react with hydroxyl species to form enolic species. These findings can be helpful for the future design of efficient HC-SCR catalysts.
ENVIRONMENTAL SCIENCE & TECHNOLOGY
(2023)
