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| 1 | Operando HERFD-XANES and surface sensitive Δμ analyses identify the structural evolution of copper(Ⅱ) phthalocyanine for electroreduction of CO_(2)显示文摘The quantitative understanding of how atomic-level catalyst structural changes affect the reactivity of the electrochemical CO_(2)reduction reaction is challenging.Due to the complexity of catalytic systems,conventional in situ X-ray spectroscopy plays a limited role in tracing the underlying dynamic structural changes in catalysts active sites.Herein,operando high-energy resolution fluorescence-detected X-ray absorption spectroscopy was used to precisely identify the dynamic structural transformation of well-defined active sites of a representative model copper(Ⅱ)phthalocyanine catalyst which is of guiding significance in studying single-atom catalysis system.Comprehensive X-ray spectroscopy analyses,including surface sensitive△μspectra which isolates the surface changes by subtracting the disturb of bulk base and X-ray absorption near-edge structure spectroscopy simulation,were used to discover that Cu species aggregated with increasing applied potential,which is responsible for the observed evolution of C_(2)H_(4).The approach developed in this work,characterizing the active-site geometry and dynamic structural change,is a novel and powerful technique to elucidate complex catalytic mechanisms and is expected to con tribute to the rational design of highly effective catalysts. | Bingbao Mei Cong Liu Ji Li Songqi Gu Xianlong Du Siyu Lu Fei Song Weilin Xu Zheng Jiang | 2022 | Journal of Energy Chemistry2022，31，1： | 3 |
| 2 | Role of local coordination in bimetallic sites for oxygen reduction: A theoretical analysis显示文摘Understanding of the oxygen reduction reaction(ORR)mechanism for single atom catalysts is pivotal for the rational design of non-precious metal cathode materials and the commercialization of fuel cells.Herein,a series of non-precious metal electrocatalysts based on nitrogen-doped bimetallic(Fe and Co)carbide were modeled by density functional theory calculations to predict the corresponding reaction pathways.The study elucidated prior oxygen adsorption on the Fe atom in the dual site and the modifier role of Co atoms to tune the electronic structures of Fe.The reaction activity was highly correlated with the bimetallic center and the coordination environment of the adjacent nitrogen.Interestingly,the preadsorption of*OH resulted in the apparent change of metal atoms'electronic states with the d-band center shifting toward the Fermi level,thereby boosting reaction activity.The result should help promote the fundamental understanding of active sites in ORR catalysts and provide an effective approach to the design of highly efficient ORR catalysts on an atomic scale. | Yuqi Yang Hao Zhang Zhaofeng Liang Yaru Yin Bingbao Mei Fei Song Fanfei Sun Songqi Gu Zheng Jiang Yuen Wu Zhiyuan Zhu | 2020 | Journal of Energy Chemistry2020，29，5： | 1 |
| 3 | Unraveling the Dynamic Structural Evolution of Phthalocyanine Catalysts during CO_(2) Electroreduction显示文摘Understanding the atomic and electronic changes of active sites promotes the whole new sight into electrochemical carbon dioxide reduction reaction(CO_(2)RR),which provides a feasible strategy to achieve carbon neutrality.Here we employ operando high-energy resolution fluorescence-detected Xray absorption spectroscopy(HERFD-XAS)to track the structural evolution of Ni(II)phthalocyanine(NiPc),considered as the model catalysts with uniform Ni-N_(4)-C_(8) moiety,during the CO_(2)RR.The HERFD-XAS method is in favor of elucidating the interaction of the reactant/catalyst interface from the atomic electronic structure dimension,facilitating the establishment of the catalytic mechanism and the dynamic structure changes.Based on operando measurement,surface sensitive difference spectra(△μ)and spectroscopy simulation,the interfacial interactions between the active sites of NiPc and reactants are monitored and the Ni species gradually reduced by increasing the applied potential is discovered.HERFD-XAS method offers an advanced and powerful tool for elucidating the complex catalytic mechanism in further various systems. | Jianing Mao Bingbao Mei Ji Li Shuai Yang Fanfei Sun Siyu Lu Wei Chen Fei Song Zheng Jiang | 2022 | Chinese Journal of Structural Chemistry2022，41，10： | 1 |
| 4 | Intrinsic spin shielding effect in platinum-rare-earth alloy boosts oxygen reduction activity显示文摘Oxygen reduction reactions(ORRs)involve a multistep proton-coupled electron process accompanied by the conversion of the apodictic spin configuration.Understanding the role of spin configurations of metals in the adsorption and desorption of oxygen intermediates during ORRs is critical for the design of efficient ORR catalysts.Herein,a platinum-rare-earth-metal-based alloy catalyst,Pt_(2)Gd,is introduced to reveal the role of spin configurations in the catalytic activity of materials.The catalyst exhibits a unique intrinsic spin reconfiguration because of interactions between the Gd-4f and Pt-5d orbitals.The adsorption and desorption of the oxygen species are optimized by modifying the spin symmetry and electronic structures of the material for increased ORR efficiency.The Pt_(2)Gd alloy exhibits a half-wave potential of 0.95 V and a superior mass activity of 1.5 A·mg Pt^(−1)in a 0.1 M HClO_(4)electrolyte,as well as higher durability than conventional Pt/C catalysts.Theoretical calculations have proven that the spin shielding effect of Gd pairs increases the spin symmetry of Pt-5d orbitals and adsorption preferences toward spin-polarized intermediates to facilitate ORR.This work clarifies the impact of modulating the intrinsic spin state of Pt through the interaction with the local high spin 4f orbital electrons in rare-earth metals,with the aim of boosting the spin-related oxygen reduction reaction,thus fundamentally contributing to the understanding of new descriptors that control ORR activity. | Siyuan Zhu Mingzi Sun Bingbao Mei Liting Yang Yuyi Chu Zhaoping Shi Jingsen Bai Xian Wang Zheng Jiang Changpeng Liu Bolong Huang Junjie Ge Wei Xing | 2023 | National Science Review2023，10，9： | 0 |
| 5 | Unveiling the mechanism of charge compensation in Li_(2)Ru_(x)Mn_(1-x)O_(3)by tracking atomic structural evolution显示文摘The relationship between the structural evolution and redox of Li-rich transition-metal layered oxides(LLOs)cathodes remains ambiguous,obstructing the development of high-performance lithium-ion(Li^(+))battery.Herein,the coherent effects of local atomic and electronic structure in Li_(2)Ru_(x)Mn_(1-x)O_(3)(LRMO)with a wide voltage window(1.3–4.8 V)is identified by in situ X-ray absorption fine spectroscopy(XAFS)and chemometrics.We not only skillfully separated the redox active structures to track the electrochemical path,but also visualized the coupling mechanism between the evolution of Ru-Ru dimer and the(de)excitation of cations and anions.Furthermore,introducing manganese triggers the“heterogeneity”of coordination environment and electronic structure between Ru and Mn after discharge to 3 V.The change of thermodynamic and kinetic paths affects the relithiation,and further leads to the hysteresis of the anion activation structure relaxation of Li_(2)Ru_(0.4)Mn_(0.6)O_(3)relative to Li_(2)RuO_(3)(LRO).Additionally,it is demonstrated that the high charge cut-off voltage restrains the relaxation of anionic active structure in LRO from a new perspective through comparative experiments.Our work associates the evolution of atomic structure with charge compensation and negative electrochemical reactions such as voltage hysteresis(VH)and capacity attenuation,deepening the understanding electrochemical reaction mechanism of LLOs during the first cycle and providing a theoretical support for the further design and synthesis of high-efficiency cathodes. | Ji Li Hongzhou Liu Shun Zheng Yande Li Daming Zhu Fanfei Sun Jingyuan Ma Songqi Gu Panzhe Qiao Shuai Yang Xianlong Du Xiaosong Liu Zhi Liu Bingbao Mei Zheng Jiang | 2022 | Journal of Energy Chemistry2022，，12： | 0 |
| 6 | Boosting hydrogen peroxide production via establishment and reconstruction of single-metal sites in covalent organic frameworks显示文摘Covalent organic frameworks(COFs)have been well developed in electrocatalytic systems owing to their controllable skeletons,porosities,and functions.However,the catalytic process in COFs remains underexplored,hindering an in-depth understanding of the catalytic mechanism.In this work,uniform Pt-N_(1)O_(1)Cl_(4)sites chelated via C-N and C=O bonds along the one-dimensional and open channels of TP-TTA-COF were established.Different from conventional single-metal sites constructed for the near-free platinum for hydrogen evolution,the as-constructed PtCl-COF showed 2e−oxygen reduction for H_(2)O_(2)production.We tracked the dynamic evolution process of atomic Pt sites in which Pt-N_(1)O_(1)Cl_(4)was transformed into Pt-N_(1)O_(1)(OH)_(2)using in situ X-ray adsorption.The theoretical calculations revealed that the strong Pt-support interaction in Pt-N_(1)O_(1)(OH)_(2)facilitated*OOH formation and thus led to higher selectivity and activity for the oxygen reduction reaction in the 2e−pathway.This work can expand the applications of COFs through the regulation of their local electronic states for the manipulation of the metal center. | Shuai Yang Lanlu Lu Ji Li Qingqing Cheng Bingbao Mei Xuewen Li Jianing Mao Panzhe Qiao Fanfei Sun Jingyuan Ma Qing Xu Zheng Jiang | 2023 | SusMat2023，3，3： | 0 |
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