DALTON TRANSACTIONS
·
2022
·Vol. 51
·期 29
·11163-11168
·
IF 4.569
Shuhui Fan,Fei Zhao,Xuansheng Wang,Qi Wang,Qiang Zhao,Jinping Li,Guang Liu
The electrochemical ammonia synthesis is an environmentally friendly method for ammonia production; however, it is still impeded by the bottleneck of N2 activation and challenging hydrogen evolution reaction (HER). A rational design for developing efficient electrocatalysts by tuning the surface electronic state is regarded as a promising strategy to overcome these obstacles. Herein, we report a phosphorus-doped potassium peroxyniobate (KNb3O8, denoted as P-KNO) electrocatalyst with enriched oxygen vacancies to effectively improve N2-to-NH3 efficiency and suppress HER. Such P-KNO electrocatalyst achieves a rate of 23.01 μg h−1 mgcat−1 for NH3 production at −0.45 V vs. reversible hydrogen electrode (RHE) and a faradaic efficiency (FE) of 39.77% at −0.4 VRHE in a 0.1 M Na2SO4 electrolyte, which is about twice that of the non-modified KNb3O8 (denoted as KNO, 11.35 μg h−1 mgcat−1, 19.60%) counterpart under the same condition. Moreover, the resultant P-KNO electrocatalyst renders steady NH3 yield amounts and selectivity in cycling tests for 10 h. It is concluded that the enhanced N2 fixation activity and faradaic efficiency are ascribed to the phosphorus doping and formation of oxygen vacancies, which not only make the surface of the electrocatalyst highly hydrophobic but also adjust the surface electronic structure of potassium niobate, thus resulting in accelerated N2 adsorption and activation during the NRR process. This electrocatalyst with phosphorus-doping and oxygen vacancies gives deep insights into the rational regulation of the surface electronic state of NRR electrocatalysts for efficient NH3 synthesis.
研究领域:
材料科学
·
电化学
·
催化科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Materials Chemistry Frontiers
·
2022
·Vol. 6
·期 16
·2190-2200
·
IF 8.683
Chengguang Liu,Xiaolei Guo,Zhen-Feng Huang,Jinheng Li,Li Gan,Lun Pan,Chengxiang Shi,Xiangwen Zhang,Guidong Yang,Ji-Jun Zou
Due to the utilization of renewable energy and proton sources, the electrochemical nitrogen reduction reaction is considered as an efficient, sustainable, and carbon-neutral route to replace the industrial Haber–Bosch process. However, restricted by the highly competitive hydrogen evolution reaction and the highly inert NN bond, electrochemical nitrogen reduction research still faces significant challenges with a low level of selectivity and activity. Herein, we demonstrate a catalyst (PdCu/TiO2−x) composed of oxygen vacancy-rich TiO2−x nanosheets and PdCu alloy nanoparticles by the co-reduction method of metal precursors. Such a catalyst exhibits excellent electrocatalytic performance at room temperature and pressure, with an NH3 yield rate of 8.51 mmol gcat−1 h−1 and the corresponding faradaic efficiency of 49.09% at −0.1 V vs. the reversible hydrogen electrode, which are much higher than most reported palladium-based catalysts and their alloy catalysts. Characterization and experimental results confirm that by properly constructing the surface defect and nanoalloy structure, the optimized electronic structure and synergistic effect can not only effectively improve the N2 adsorption and activation, but also reduce the reaction barrier, resulting in efficient electrocatalytic performance. Meanwhile, the introduction of Cu accelerates the hydrogen desorption, further effectively improving the faradaic efficiency. Overall, we explored the electrocatalytic performance and mechanism of the bimetal alloy catalyst, as well as the optimization strategies for enhancing the nitrogen mass transfer process, providing new insight into the rational design of a highly efficient e-NRR system through tuning of the catalyst and reaction environment.
研究领域:
材料科学
·
电化学
✓ 已验证
产品关联
DOI
高影响因子
APPLIED CATALYSIS B-ENVIRONMENTAL
·
2022
·
IF 24.319
Mengdi Liu,Sai Zhang,Min Chen,Limin Wu
While electrochemical nitrogen reduction reaction (NRR) stands as a promising technique for sustainable NH 3 fabrication due to its mild operation conditions, it has long been suffered from low efficiency and poor selectivity owing to the inertness of N 2 and competition hydrogen evolution reaction (HER). Herein, we report the use of oxygen vacancy rich TiO 2 loaded with Au nanoparticles as NRR catalyst in super concentrated lithium bis(trifluoromethane sulfonyl) imide (Li TFSI) “water-in-salt” system (20 M electrolyte) and obtain the Faradaic efficiency of 37.2 % with an NH 3 yield rate of 20.3 μg h −1 cm −2 at − 0.4 V vs RHE, accompanied by the significant decay of both current density and onset potential of hydrogen evolution reaction. Electrochemical experimental and theoretical calculation results indicate that the HER process can be greatly hindered both kinetically and energetically. The unique effect of this “water-in-salt” electrolyte would offer a new idea to improve the NRR selectivity via HER suppression.
研究领域:
电化学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
CHINESE JOURNAL OF CATALYSIS
·
2022
·
IF 12.92
Ya Li,Zhenkang Wang,Haoqing Ji,Lifang Zhang,Tao Qian,Chenglin Yan,Jianmei Lu
As an essential raw material for fertilizer production and promising green fuels, ammonia is significant to the national economy and social development. Recently, nitrogen reduction reaction (NRR) towards ammonia under mild conditions has received intensive attention due to environmental friendliness and low energy consumption, compared to the rigorous and contaminative Haber-Bosch process. However, as current research deepens, some fatal challenges emerged in this field–not only high volatility and low repeatability but false–positive results, casting serious doubts about its prospects. In this review, we summarized and discussed some potential factors that possibly induce false-positive results for accurate ammonia quantification, including the aspects of catalyst materials, experimental process, and quantification methods. And corresponding methods to eliminate these effects are also summarized. Furthermore, a promising protocol and several control principles are proposed to eliminate potential errors during ammonia quantification. This review establishes a paradigm base in NRR research field toward more accurate ammonia quantification.
研究领域:
化学
·
环境科学
·
材料科学
✓ 已验证
DOI
高影响因子
ACS Applied Materials & Interfaces
·
2021
·
IF 9.229
Haijun Chen,Jie Liang,Li Li,Baozhan Zheng,Zhesheng Feng,Zhaoquan Xu,Yonglan Luo,Qian Liu,Xifeng Shi,Yang Liu,Shuyan Gao,Abdullah M. Asiri,Yan Wang,Qingquan Kong,Xuping Sun
Electrocatalytic nitrogen reduction reaction (NRR) enabled by introducing Ti3+ defect sites into TiO2 through a doping strategy has recently attracted widespread attention. However, the amount of Ti3+ ions is limited due to the low concentration of dopants. Herein, we propose Ti2O3 nanoparticles as a pure Ti3+ system that performs efficiently toward NH3 electrosynthesis under ambient conditions. This work has suggested that Ti3+ ions, as the main catalytically active sites, significantly increase the NRR activity. In an acidic electrolyte, Ti2O3 achieves extraordinary performance with a high NH3 yield and a Faradaic efficiency of 26.01 μg h–1 mg–1 cat. and 9.16%, respectively, which are superior to most titanium-based NRR catalysts recently reported. Significantly, it also demonstrates a stable NH3 yield in five consecutive cycles. Theoretical calculations uncovered that the enhanced electrocatalytic activity of Ti2O3 originated from Ti3+ active sites and significantly lowered the overpotential of the potential-determining step.
研究领域:
材料科学
·
电化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
·
2023
·
IF 7.2
Shuhui Fan,Yanan Hu,Tan Zhang,Qiang Zhao,Jinping Li,Guang Liu
The synthesis of ammonia via electrochemical nitrogen reduction reaction (NRR) provides an attractive alternative approach to the traditional Haber-Bosch process. In this regard, a one-step hydrothermal method was adopted to synthesize a bimetallic oxide， ferric molybdate (Fe 2 (MoO 4 ) 3 ), coated with carbon black on the surface (denoted as Fe 2 (MoO 4 ) 3 /C). The carbon black coating minimizes aggregation of Fe 2 (MoO 4 ) 3 , leading to increased electrochemical active sites for NRR. Additionally, this coating improves the electrical conductivity of Fe 2 (MoO 4 ) 3 thereby accelerating electron transfer between carbon black and Fe 2 (MoO 4 ) 3 , which is beneficial to charge transfer and enlarge the electrochemical active surface areas. At a potential of −0.4 V RHE (vs. reversible hydrogen electrode , RHE), the ammonia yield achieved was up to 51.76 μg h −1 mg cat −1 , with a Faradaic efficiency of 90.63% at −0.35V RHE . Impressively, this electrocatalyst exhibited excellent cycle stability and durability.
研究领域:
化学
·
环境科学
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材料科学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2024
·
IF 5.8
Ze Gao,Renming Liu,Daming Yang,Hongji Xu,Yuqi Wang,Bowen Li,Ming Feng,Ting Wang,Gangyong Jin
The adsorption and activation of N 2 as well as the competitive hydrogen evolution reaction (HER) pose significant challenges to the electrocatalytic nitrogen reduction reaction (ENRR), which severely limits its industrial application. Therefore, exploring the ENRR electrocatalysts with high activity and selectivity is an extremely important task. In this work, the oxygen vacancy-rich Fe 2 O 3 /Co 3 O 4 heterostructures (referred to as Vo-X-Fe 2 O 3 /Co 3 O 4 ) were rationally designed by employing Co 3 O 4 as a template via a simple hydrothermal and subsequent calcination method, which acted as highly efficient ENRR electrocatalysts. The electrocatalytic activity of Vo-X-Fe 2 O 3 /Co 3 O 4 can be easily regulated by optimization of the Fe content and the introduction of oxygen vacancy (Vo). The results demonstrate that the optimized Vo-1.0-Fe 2 O 3 /Co 3 O 4 catalyst achieves a high NH 3 yield of 47.37 μg h −1 mg cat −1 and a Faradaic efficiency (FE) of 22.42 %. Moreover, the excellent stability and reproducibility are also demonstrated. The comprehensive characterizations reveal that the exceptional performance of Vo-1.0-Fe 2 O 3 /Co 3 O 4 can be attributed to the improved N 2 adsorption and activation, restricted competitive HER and promoted electron transfer kinetics induced by the synergistic introduction of Vo and Fe. This work emerged a new speculating orientation for rational design of ENRR catalysts.
研究领域:
材料科学
·
催化化学
✓ 已验证
产品关联
DOI
高影响因子
Materials Chemistry Frontiers
·
2024
·
IF 6
Huhu Yin,Ziyang Song,Xiujing Xing,Ling Miao,Yaokang Lv,Lihua Gan,Mingxian Liu,Wei Xiong
Manganese molybdate has been shown to be an excellent NRR catalyst due to its uniform rod-like structure and large specific surface area, and in order to further improve its catalytic performance, MnMoO4 has been modified using an elemental doping strategy. Here, we developed a simple scheme for doping elemental Bi into MnMoO4 and explored the effects of different doping amounts on the properties of MnMoO4 by adjusting the amount of Bi dopant. The results showed that Bi was successfully introduced into the lattice of MnMoO4 and induced lattice perturbations and led to the generation of more oxygen vacancies. 6% Bi–MnMoO4 exhibited good catalytic performance with an NH3 yield of 19.22 μg h−1 mgcat.−1 and high FE (17.13%) at −0.40 V (vs.RHE) and also exhibited excellent electrochemical stability and structural durability. Cyclic voltammetry cycling tests reveal an increased electrochemical active surface area, exposing more active sites and thereby demonstrating superior electrocatalytic activity, as well as exceptional electrochemical stability and structural durability. This study provides new strategies for constructing efficient nitrogen reduction reaction catalysts.
研究领域:
材料科学
·
电催化
✓ 已验证
产品关联
DOI
高影响因子
Small
·
2022
·Vol. 18
·期 39
·2203284
·
IF 15.153
Shi Bian,Qian Liu,Xue Zhang,Chao Ma,Yanli Zhang,Ziqiang Cheng,Yihong Kang,Wei Lu,Paul K. Chu,Xue-Feng Yu,Jiahong Wang
Although constructing heterostructures is considered as one of the most successful strategies to improve the activity of a catalyst, the heterostructures usually suffer from the cumbersome preparation treatments and low-yield. Inspired by a solid-phase solution-precipitation (SPSP) process, an approach for interface intensive heterostructures with high yield is developed. Herein, a black-phosphorus/iron-tetraphosphide (BP/FeP 4 ) heterostructure is prepared mechanochemically with high transient pressure by the solid-phase ball milling approach. The BP/FeP 4 heterostructure delivers excellent catalytic performance in the nitrogen reduction reaction (NRR) as exemplified by an NH 3 yield of 77.6 µg h −1 mg cat . − 1 \[{\rm{mg}}_{{\rm{cat}}{\rm{.}}}^{{\bm{ - }}1}\] and Faradic efficiency of 62.9% (−0.2 V), which are superior to that of most NRR catalysts recently reported. Experimental investigation and density-functional theory calculation indicate the importance of excess phosphorus in the heterostructures on the NRR activity, which assists the Fe atom to activate N 2 via adsorbing the H atom. The results demonstrate the great potential of this new type of heterostructures prepared by the SPSP approach. Benefiting from the simple preparation process and low cost, the heterostructures offer a new insight into the development of highly efficient catalysts.
研究领域:
材料科学
·
催化化学
✓ 已验证
DOI
高影响因子
APPLIED CATALYSIS B-ENVIRONMENTAL
·
2022
·
IF 24.319
Chaoqun Ma,Yanli Zhang,Shihai Yan,Bingping Liu
h-BN -based electrocatalysts with low-cost and high efficiency have a great potential for electrochemical nitrogen reduction reaction (NRR). The carbon-doped boron nitride ( C-BN ) nanosheets are proposed as the excellent metal-free electrocatalysts for converting nitrogen to ammonia (NH 3 ). In 0.1 M Na 2 SO 4 solution, it obtains NH 3 yield of 44.59 ± 1.79 μg h −1 mg cat −1 at − 0.9 V vs reversible hydrogen electrode (RHE), with a high faradaic efficiency (FE) of 13.27 ± 0.42 % at − 0.7 V vs RHE, and an outstanding electrochemical durability. Density functional theory (DFT) calculations reveal that carbon-doping dramatically reduces the band gap to 1.40 eV and induces charge accumulation on carbon atom to facilitate N 2 adsorption. The synergistic interaction of C and B atoms at the double-active-site of C-BN significantly decreases the energy barrier (from *NH-NH to *NH-NH 2 ) for the potential-determining step. The results confirm that C-BN has the potential as an efficient metal-free NRR electrocatalyst in neutral media.
研究领域:
材料科学
·
电化学
·
理论计算
✓ 已验证
DOI
高影响因子
ACS Sustainable Chemistry & Engineering
·
2020
·
IF 7.632
Ziqiang Wang,Jinhua Niu,You Xu,Liang Wang,Hongjing Wang,Huazhang Liu
Electrochemical nitrogen reduction reaction (NRR) has been regarded as an attractive approach for ammonia synthesis under ambient condition, and it is critical to develop efficient catalysts with facile nitrogen adsorption and activation for NRR. Herein, we report the construction of metal–nonmetal AuCuB porous nanostructures (AuCuB PNSs) as highly active electrocatalysts for NRR via a one-step process, and the interconnected porous structure and boron doping provide sufficient active sites and enhanced nitrogen adsorption energy for electrocatalytic NRR. As such, the AuCuB PNSs possess a high NH3 yield (13.2 μg h–1 mgcat–1) and Faraday efficiency (12.78%) in neutral media, as well as excellent stability. This work provides a valuable strategy for rationally designing B-doped metallic electrocatalysts with desired compositions, which behave as high-efficiency catalysts toward electrochemical ammonia synthesis.
研究领域:
材料科学
·
电化学
✓ 已验证
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2021
·
IF 13.273
Yajie Bai,Jianmin Lu,Hongye Bai,Zhenyuan Fang,Fagen Wang,Ying Liu,Dongtian Sun,Bifu Luo,Weiqiang Fan,Weidong Shi
The photoelectrochemical N 2 reduction reaction (PEC NRR) is extremely charming to the synthetic ammonia (NH 3 ), for its mild operating conditions and low carbon footprint. Taking account of the strong chemical inertness of N 2 and competitive hydrogen evolution reaction, it is necessary to explore a robust and stable photoelectrocatalyst. Herein, a robust p-type BiVO 4 (p-BiVO 4 ) photocathode is firstly reported for NRR under ambient conditions. Interestingly, V sites are proved as the mainly ideal active center for N 2 adsorption/activation based on the density functional theory (DFT) calculations. The ammonia evolution rate ( V NH3 : 11.6 × 10 −8 mol h −1 cm −2 ) and Faradaic efficiency (16.2%) were obtained at −0.1 V vs. RHE in 0.1 M Li 2 SO 4 solution, outperforming most of the photoelectrocatalysts reported thus far. Moreover, the 1 H nuclear magnetic resonance result confirmed that the source of N was completely from the feeding N 2 gas. This work provided a new opportunity to tap the V-based photocathode in the field of PEC NRR.
研究领域:
材料科学
·
催化化学
·
能源化学
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）