ACS Applied Materials & Interfaces
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2024
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IF 8.3
Xue-Bo Liu,Rui Zhao,Min-Min Xu,Shang-Xiong Wei,Xue-Feng Cheng,Jing-Hui He
The electrochemical reduction of nitrate to ammonia (NO3RR) provides a desired alternative of the traditional Haber–Bosch route for ammonia production, igniting a research boom in the development of electrocatalysts with high activity. Among them, molecular electrocatalysts hold considerable promise for the NO3RR, suppressing the competing hydrogen evolution reaction. However, the complicated synthesis procedure, usage of environmentally unfriendly organic solvents, and poor stability of Cu-based molecular electrocatalysts greatly limit their employment in NO3RR, and the development of desired Cu-based molecular catalysts remains challenging. Herein, a simple nonorganic solvent involving a one-step strategy was proposed to synthesize d−π-conjugated molecular electrocatalysts metal–amidinothiourea (M-ATU). Cu-ATU is composed of Cu coordinated with two S and two N atoms, whereas Ni-ATU is formed by Ni with four N atoms from two ATU ligands. Remarkably, Cu-ATU with a Cu–N2S2 coordination configuration exhibits superior NO3RR activity with a NH3 yield rate of 159.8 mg h–1 mgcat–1 (−1.54 V) and Faradaic efficiency of 91.7% (−1.34 V), outperforming previously reported molecular catalysts. Compared to Ni-ATU, Cu-ATU transfers more electrons to the *NO intermediate, effectively breaking the strong sp2 hybridization system and weakening the energy of N═O bonds. The increase in free energy of *NO reduced the energy barriers of the rate-determining step, facilitating the further hydrogenation process over Cu-ATU. Our work opened up a new horizon for exploring molecular electrocatalysts for nitrate activation and paved a way for the in-depth understanding of catalytic behaviors, aligning more closely with industrial demands.
研究领域:
化学
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环境科学
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材料科学
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PubMed
高影响因子
JOURNAL OF COLLOID AND INTERFACE SCIENCE
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2025
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IF 9.7
Yahui Zhu,Xiaohua Ma,Wenjie Lai,Zengxiang Tang,Weiming Xiao,Rong Zeng,Shunmin Ding,Chao Chen
D-π conjugated coordination polymers (CCPs) are often widely used in photocatalysis and electrocatalysis due to their unique electronic conductivity and structural flexibility. However, it remains a challenge to overcome the self-degradation of d-π CCPs in thermal catalysis and to effectively utilize their excellent electron transfer properties. Here, we present a series of d-π CCPs derivative after calcination treatment. The derivatives were optimized for overall electron cloud density by constructing two-dimensional pyridinic-nitrogen (N) doped carbon carriers, which exhibited the inherent π-electron delocalization and charge transfer properties of d-π CCPs. The presence of electron transfer was confirmed by X-ray Photoelectron Spectroscopy (XPS), Raman and kinetic analysis, demonstrating that this d-π CCPs derivative possesses excellent electron conduction ability and low activation energies for the reaction. Density-functional theory (DFT) calculations further confirmed the modulation of the nickel nanoparticles (Ni NPs) electronic state by the carriers, which resulted in strong Ni NPs interactions with the high-electron-density π-bonds of the C C bond. This property significantly enhances the target adsorption and activation of the C C bond, leading to a substantial enhancement of the reaction performance. This strategy provides a new development direction for the application of d-π CCPs in thermal catalysis.
研究领域:
材料科学
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催化化学
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PubMed
高影响因子
Nature Communications
·
2022
·Vol. 13
·期 1
·1-10
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IF 17.694
Wang Qiyou,Liu Kang,Hu Kangman,Cai Chao,Li Huangjingwei,Li Hongmei,Herran Matias,Lu Ying-Rui,Chan Ting-Shan,Ma Chao,Fu Junwei,Zhang Shiguo,Liang Ying,Cortés Emiliano,Liu Min
Atomically dispersed transition metals on carbon-based aromatic substrates are an emerging class of electrocatalysts for the electroreduction of CO 2 . However, electron delocalization of the metal site with the carbon support via d-π conjugation strongly hinders CO 2 activation at the active metal centers. Herein, we introduce a strategy to attenuate the d-π conjugation at single Ni atomic sites by functionalizing the support with cyano moieties. In situ attenuated total reflection infrared spectroscopy and theoretical calculations demonstrate that this strategy increases the electron density around the metal centers and facilitates CO 2 activation. As a result, for the electroreduction of CO 2 to CO in aqueous KHCO 3 electrolyte, the cyano-modified catalyst exhibits a turnover frequency of ~22,000 per hour at −1.178 V versus the reversible hydrogen electrode (RHE) and maintains a Faradaic efficiency (FE) above 90% even with a CO 2 concentration of only 30% in an H-type cell. In a flow cell under pure CO 2 at −0.93 V versus RHE the cyano-modified catalyst enables a current density of −300 mA/cm 2 with a FE above 90%.
研究领域:
催化化学
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电化学
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材料科学
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DOI
PubMed
高影响因子
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
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2025
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IF 3.9
Zi-Yan Li,Jing-Ru Zhang,Qing-Yi Ma,Wen-Qian Leng,Fei-Peng Du,Hao-Han Zhou,Yun-Fei Zhang
Single-walled carbon nanotubes (SWCNTs) are considered promising materials for future flexible thermoelectric applications due to their high electrical conductivity and tunable thermoelectric properties. However, the mutual constraints between their Seebeck coefficients and electrical conductivity severely limit further improvements for thermoelectric performance. In this study, we propose a doping strategy based on transition metal ions (TMIs) to break through the bottleneck of SWCNT-based materials by synergistically regulating the carrier concentration and mobility. Five low-cost metal ions (Fe3+, Co2+, Ni2+, Cu2+, and Zn2+) were employed as dopants to systematically investigate the thermoelectric properties of TMI/SWCNT films. The Cu2+-doped SWCNT exhibited optimal performance, achieving an electrical conductivity of 4051.84 S·cm–1, 10.66 times higher than that of pristine SWCNTs, and a power factor (PF) of 153.76 μW·m–1·K–2. Through X-ray photoelectron spectroscopy (XPS) and Raman spectra, the performance enhancement originates from a dual synergistic mechanism: (1) charge transfer between Cu2+ and SWCNTs effectively increases the hole concentration; (2) formation of a d–π conjugation system between d-orbitals of transition metal and the tubular π-electron cloud of SWCNTs constructs highly efficient charge-transport channels and reduces carrier migration resistance. A nine-pair thermoelectric module fabricated with the optimized material demonstrated an output power of 1.18 μW under a 60 K temperature gradient. This study provides both theoretical insights and a technical pathway for developing highly efficient, flexible, and low-cost SWCNT-based thermoelectric devices.
研究领域:
材料科学
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纳米技术
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热电材料
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能量转换
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掺杂
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高影响因子
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