Ding Yuan, Yuhai Dou, Chun‐Ting He, Linping Yu, Li Xu, David Adekoya, Qingbing Xia, Jianmin Ma, Shixue Dou, Shanqing Zhang
Transition metal sulfides have been demonstrated to be more active electrocatalysts than the corresponding (hydr)oxides for oxygen evolution reaction (OER). The nature of active sites, however, remains unclear. Herein, we study whether S could promote the OER activity of FeCoOOH and try to identify the catalytically active centers. Density functional theory suggests that two coordinating S could work synergistically with one adjacent Fe to optimize the electronic states of Co, resulting in decreased binding energy of OH* (ΔEOH) while little changed ΔEOH, and thus significantly lowering the catalytic overpotential. Further experimental studies validate the synergistic effect between S and Fe on tuning the electronic structure and the greatly improved catalytic activity with a small overpotential of 205.4 mV to drive 20 mA cm-2. This study unveils the origin of the high catalytic activity of transition metal sulfides and provides insights into the design of efficient OER electrocatalysts.
在析氧反应(OER)中,过渡金属硫化物已被证明是比相应的(氢)氧化物更活跃的电催化剂。然而,活性位点的性质仍不清楚。本文研究S是否能促进FeCoOOH的OER活性,并试图确定催化活性中心。密度泛函理论认为,两个配位的S可以与相邻的Fe协同作用,优化Co的电子态,使OH* (ΔEOH)的结合能降低,而ΔEOH的变化不大,从而显著降低催化过电位。进一步的实验研究证实了S和Fe在调节电子结构方面的协同作用,并大大提高了催化活性,以205.4 mV的小过电位驱动20 mA cm-2。该研究揭示了过渡金属硫化物高催化活性的起源,并为高效OER电催化剂的设计提供了见解。
{"title":"S Doping Optimized Intermediate Energetics of FeCoOOh for Enhanced Oxygen Evolution Catalytic Activity","authors":"Ding Yuan, Yuhai Dou, Chun‐Ting He, Linping Yu, Li Xu, David Adekoya, Qingbing Xia, Jianmin Ma, Shixue Dou, Shanqing Zhang","doi":"10.2139/ssrn.3736398","DOIUrl":"https://doi.org/10.2139/ssrn.3736398","url":null,"abstract":"Transition metal sulfides have been demonstrated to be more active electrocatalysts than the corresponding (hydr)oxides for oxygen evolution reaction (OER). The nature of active sites, however, remains unclear. Herein, we study whether S could promote the OER activity of FeCoOOH and try to identify the catalytically active centers. Density functional theory suggests that two coordinating S could work synergistically with one adjacent Fe to optimize the electronic states of Co, resulting in decreased binding energy of OH* (ΔEOH) while little changed ΔEOH, and thus significantly lowering the catalytic overpotential. Further experimental studies validate the synergistic effect between S and Fe on tuning the electronic structure and the greatly improved catalytic activity with a small overpotential of 205.4 mV to drive 20 mA cm-2. This study unveils the origin of the high catalytic activity of transition metal sulfides and provides insights into the design of efficient OER electrocatalysts.","PeriodicalId":299681,"journal":{"name":"ChemRN: Inorganic Catalysis (Topic)","volume":"51 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-11-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130186069","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
B. Rajeeva, Pranaw Kunal, P. Kollipara, Palash V. Acharya, M. Joe, Matthew S. Ide, K. Jarvis, Yuanyue Liu, V. Bahadur, S. M. Humphrey, Yuebing Zheng
Accumulation-mediated chemical reactions are a ubiquitous phenomenon in nature. Herein, we explore microbubble-induced accumulation of precursor ions to achieve surfactant-free synthesis of immiscible metallic nanoalloys and to simultaneously pattern the nanoalloys into targeted architectures for their enhanced catalytic applications. We name our approach as a unified spatiotemporal synthesis and structuring (US3) strategy, wherein millisecond-scale accumulation of the precursor ions in a highly confined laser-mediated microbubble trap (MBT) drives ultra-fast alloy synthesis in sync with the structuring process. As a case-in-point, we employ US3 strategy for the in-situ surfactant-free synthesis and patterning of traditionally immiscible rhodium-gold (RhAu) nanoalloys. Stochastic random walk simulations justify the millisecond-scale accumulation process, leading to a 3-order reduction in synthesis time. The catalytic activity and structure-property relationship of the structured nanoalloys were evaluated using the reduction of p-nitrophenol with NaBH4. Our in-situ synthesis and structuring strategy can be translated for high-throughput production and screening of multi-metallic systems with tailored catalytic, opto-electronic, and magnetic functions.
{"title":"Accumulation-Driven Surfactant-Free Synthesis of Architectured Immiscible Metallic Nanoalloys with Enhanced Catalysis","authors":"B. Rajeeva, Pranaw Kunal, P. Kollipara, Palash V. Acharya, M. Joe, Matthew S. Ide, K. Jarvis, Yuanyue Liu, V. Bahadur, S. M. Humphrey, Yuebing Zheng","doi":"10.2139/ssrn.3372970","DOIUrl":"https://doi.org/10.2139/ssrn.3372970","url":null,"abstract":"Accumulation-mediated chemical reactions are a ubiquitous phenomenon in nature. Herein, we explore microbubble-induced accumulation of precursor ions to achieve surfactant-free synthesis of immiscible metallic nanoalloys and to simultaneously pattern the nanoalloys into targeted architectures for their enhanced catalytic applications. We name our approach as a unified spatiotemporal synthesis and structuring (US3) strategy, wherein millisecond-scale accumulation of the precursor ions in a highly confined laser-mediated microbubble trap (MBT) drives ultra-fast alloy synthesis in sync with the structuring process. As a case-in-point, we employ US3 strategy for the in-situ surfactant-free synthesis and patterning of traditionally immiscible rhodium-gold (RhAu) nanoalloys. Stochastic random walk simulations justify the millisecond-scale accumulation process, leading to a 3-order reduction in synthesis time. The catalytic activity and structure-property relationship of the structured nanoalloys were evaluated using the reduction of p-nitrophenol with NaBH4. Our in-situ synthesis and structuring strategy can be translated for high-throughput production and screening of multi-metallic systems with tailored catalytic, opto-electronic, and magnetic functions.","PeriodicalId":299681,"journal":{"name":"ChemRN: Inorganic Catalysis (Topic)","volume":"32 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-04-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131938173","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
A new cobalt-based catalyst, [(btep)CoBr 2 ] is produced by the reaction of CoBr 2 and bis(methylthioether)pyridine (btep), and its structure has been determined by X-ray crystallography. Our experiments suggest that this cobalt complex can used as a molecular catalyst for electrochemical and photochemical driven hydrogen evolution. As an electrocatalyst, this cobalt complex can provide 591.9 moles of hydrogen per mole of catalyst per hour (mol H 2 /mol catalyst/h) from a neutral water under an overpotential (OP) of 837.6 mV. As a co-catalyst, it was mixed with CdS nanorods (CdS NRs) as a photosensitizer, and ascorbic acid (H 2 A) as a sacrificial electron donor, and [(btep)CoBr 2 ] can provide 9326.4 mol H 2 per mole of catalyst during 40 h irradiation. The highest apparent quantum yield (AQY) is ~25.5%. The catalytic mechanism for H 2 production is investigated by several measurements and analysis.
{"title":"A Cobalt Complex of Bis(Methylthioether)Pyridine Catalyst for Hydrogen Evolution from Water","authors":"Chun‐Li Wang, Weixia Liu, Shu‐Zhong Zhan","doi":"10.2139/ssrn.3597978","DOIUrl":"https://doi.org/10.2139/ssrn.3597978","url":null,"abstract":"A new cobalt-based catalyst, [(btep)CoBr 2 ] is produced by the reaction of CoBr 2 and bis(methylthioether)pyridine (btep), and its structure has been determined by X-ray crystallography. Our experiments suggest that this cobalt complex can used as a molecular catalyst for electrochemical and photochemical driven hydrogen evolution. As an electrocatalyst, this cobalt complex can provide 591.9 moles of hydrogen per mole of catalyst per hour (mol H 2 /mol catalyst/h) from a neutral water under an overpotential (OP) of 837.6 mV. As a co-catalyst, it was mixed with CdS nanorods (CdS NRs) as a photosensitizer, and ascorbic acid (H 2 A) as a sacrificial electron donor, and [(btep)CoBr 2 ] can provide 9326.4 mol H 2 per mole of catalyst during 40 h irradiation. The highest apparent quantum yield (AQY) is ~25.5%. The catalytic mechanism for H 2 production is investigated by several measurements and analysis.","PeriodicalId":299681,"journal":{"name":"ChemRN: Inorganic Catalysis (Topic)","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129221439","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}