High-efficiency nitrate electroreduction to ammonia on electrodeposited cobalt–phosphorus alloy film

2021 ◽  
Vol 57 (76) ◽  
pp. 9720-9723
Author(s):  
Zerong Li ◽  
Guilai Wen ◽  
Jie Liang ◽  
Tingshuai Li ◽  
Yonglan Luo ◽  
...  

Ti plate supported cobalt-phosphorus alloy film acts as an active and selective electrocatalyst for ambient NO3−-to-NH3 conversion. In 0.2 M Na2SO4 with 200 ppm NO3−, it offers a NH3 yield rate of 416.0 ± 7.2 μg h−1 cm−2 with a Faradaic efficiency of 93.6 ± 3.3% at −0.6 and −0.3 V vs. RHE, respectively.

2019 ◽  
Vol 55 (96) ◽  
pp. 14474-14477 ◽  
Author(s):  
Chengbo Li ◽  
Shiyong Mou ◽  
Xiaojuan Zhu ◽  
Fengyi Wang ◽  
Yuting Wang ◽  
...  

Dendritic Cu behaves as an efficient electrocatalyst for ambient N2-to-NH3 fixation with a high Faradaic efficiency of 15.12% and a large NH3 yield rate of 25.63 μg h−1 mgcat.−1 at −0.40 V versus reversible hydrogen electrode in 0.1 M HCl.


2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Wenyi Li ◽  
Ke Li ◽  
Yixing Ye ◽  
Shengbo Zhang ◽  
Yanyan Liu ◽  
...  

AbstractThe electrocatalytic nitrogen (N2) reduction reaction (NRR) relies on the development of highly efficient electrocatalysts and electrocatalysis systems. Herein, we report a non-loading electrocatalysis system, where the electrocatalysts are dispersed in aqueous solution rather than loading them on electrode substrates. The system consists of aqueous Ag nanodots (AgNDs) as the catalyst and metallic titanium (Ti) mesh as the current collector for electrocatalytic NRR. The as-synthesized AgNDs, homogeneously dispersed in 0.1 M Na2SO4 solution (pH = 10.5), can achieve an NH3 yield rate of 600.4 ± 23.0 μg h−1 mgAg−1 with a faradaic efficiency (FE) of 10.1 ± 0.7% at −0.25 V (vs. RHE). The FE can be further improved to be 20.1 ± 0.9% at the same potential by using Ti mesh modified with oxygen vacancy-rich TiO2 nanosheets as the current collector. Utilizing the aqueous AgNDs catalyst, a Ti plate based two-electrode configured flow-type electrochemical reactor was developed to achieve an NH3 yield rate of 804.5 ± 30.6 μg h−1 mgAg−1 with a FE of 8.2 ± 0.5% at a voltage of −1.8 V. The designed non-loading electrocatalysis system takes full advantage of the AgNDs’ active sites for N2 adsorption and activation, following an alternative hydrogenation mechanism revealed by theoretical calculations.


2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Ji-Yong Kim ◽  
Deokgi Hong ◽  
Jae-Chan Lee ◽  
Hyoung Gyun Kim ◽  
Sungwoo Lee ◽  
...  

AbstractFor steady electroconversion to value-added chemical products with high efficiency, electrocatalyst reconstruction during electrochemical reactions is a critical issue in catalyst design strategies. Here, we report a reconstruction-immunized catalyst system in which Cu nanoparticles are protected by a quasi-graphitic C shell. This C shell epitaxially grew on Cu with quasi-graphitic bonding via a gas–solid reaction governed by the CO (g) - CO2 (g) - C (s) equilibrium. The quasi-graphitic C shell-coated Cu was stable during the CO2 reduction reaction and provided a platform for rational material design. C2+ product selectivity could be additionally improved by doping p-block elements. These elements modulated the electronic structure of the Cu surface and its binding properties, which can affect the intermediate binding and CO dimerization barrier. B-modified Cu attained a 68.1% Faradaic efficiency for C2H4 at −0.55 V (vs RHE) and a C2H4 cathodic power conversion efficiency of 44.0%. In the case of N-modified Cu, an improved C2+ selectivity of 82.3% at a partial current density of 329.2 mA/cm2 was acquired. Quasi-graphitic C shells, which enable surface stabilization and inner element doping, can realize stable CO2-to-C2H4 conversion over 180 h and allow practical application of electrocatalysts for renewable energy conversion.


Catalysts ◽  
2020 ◽  
Vol 10 (7) ◽  
pp. 802
Author(s):  
Chang Sun ◽  
Yingxin Mu ◽  
Yuxin Wang

Electrochemical ammonia synthesis, which is an alternative approach to the Haber–Bosch process, has attracted the attention of researchers because of its advantages including mild working conditions, environmental protection, and simple process. However, the biggest problem in this field is the lack of high-performance catalysts. Here, we report high-efficiency electroreduction of N2 to NH3 on γ-MnO2-supported Pd nanoparticles (Pd/γ-MnO2) under ambient conditions, which exhibits excellent catalytic activity with an NH3 yield rate of 19.72 μg·mg−1Pd h−1 and a Faradaic efficiency of 8.4% at −0.05 V vs. the reversible hydrogen electrode (RHE). X-ray diffraction (XRD) and transmission electron microscopy (TEM) characterization shows that Pd nanoparticles are homogeneously dispersed on the γ-MnO2. Pd/γ-MnO2 outperforms other catalysts including Pd/C and γ-MnO2 because of its synergistic catalytic effect between Pd and Mn.


2020 ◽  
Vol 56 (3) ◽  
pp. 446-449 ◽  
Author(s):  
Shenglin Xiao ◽  
Fang Luo ◽  
Hao Hu ◽  
Zehui Yang

Boron and nitrogen dual-doped carbon nanospheres show exceptional nitrogen reduction reaction activity, with an NH3 yield rate of 15.7 μgNH3 h−1 mgcat.−1 and Faradaic efficiency of 8.1% at −0.4 V vs. RHE in acidic electrolyte.


2020 ◽  
Vol 56 (14) ◽  
pp. 2107-2110 ◽  
Author(s):  
Fengyi Wang ◽  
Xu Lv ◽  
Xiaojuan Zhu ◽  
Juan Du ◽  
Siyu Lu ◽  
...  

Bi nanodendrite acts as an efficient electrocatalyst for ambient N2-to-NH3 with NH3 yield rate of 25.86 μg h−1 mg−1cat. and faradaic efficiency of 10.8% at −0.60 V and −0.55 V versus RHE, respectively.


2019 ◽  
Vol 3 (1) ◽  

A composite of copper and gold nanoparticles was deposited using arc plasma deposition on the conductive FTO substrate for the electrochemical reduction of CO2 . The use of arc plasma deposition system allows the nanoparticles to be implanted onto the substrate as opposed to the commonly used methods of vacuum deposition or electro deposition. This unique structure reduced the CO2 to produce formic acid with up to 60% faradaic efficiency. Copper and gold nanoparticles have never previously been reported to produce formic acid with such high efficiency, suggesting that the co-deposition technique of implanted nanoparticles can provide an interesting future avenue in the field of electrochemical reduction of CO2 . The surface analysis of the electrodes is presented here along with potential dependent faradaic efficiency of the electro catalysis.


2020 ◽  
Vol 7 (19) ◽  
pp. 3555-3560
Author(s):  
Chang Li ◽  
Shengbo Zhang ◽  
Zhenhua Ding ◽  
Hongjian Zhou ◽  
Guozhong Wang ◽  
...  

Copper nanocrystals anchored on an O-rich carbonized corn gel for electrochemical N2 fixation to NH3 with a faradaic efficiency of 25.89% and an NH3 yield rate of 1514 μg h−1 mgCu−1 at −0.3 V versus an RHE in 0.1 M Na2SO4.


2018 ◽  
Vol 54 (81) ◽  
pp. 11427-11430 ◽  
Author(s):  
Hehan Huang ◽  
Li Xia ◽  
Xifeng Shi ◽  
Abdullah M. Asiri ◽  
Xuping Sun

An Ag nanosheet acts as a highly active electrocatalyst for N2-to-NH3 fixation. In 0.1 M HCl, this catalyst attains a high Faradaic efficiency of 4.8% and a NH3 yield rate of 4.62 × 10−11 mol s−1 cm−2 at −0.60 V vs. RHE.


Author(s):  
Khurram Shahzad ◽  
Cezarina Cela Mardare ◽  
Andrei Ionut Mardare ◽  
Achim Walter Hassel

AbstractMetal surfaces covered with oxides have attracted considerable scientific attention in various applications. In particular, anodic films fabricated by cost-effective anodizing have been widely used in nano-structured engineering to provide various surface functionalities. However, understanding of alloy film stability, having individual elements with widely varying structures and morphologies, is very limited due to lack of thermodynamic information and effects of electrolyte chemistry. This requires many tedious efforts on a trial and error basis in selecting suitable electrolytes that can produce the protective film at high efficiency on alloys having mixed chemistries. It is, therefore, crucial to develop a combination of high throughput theoretical analysis and automated rapid localized electrochemical probing that provides a fast and simple solution for electrolyte choice and paves the way to the remarkable expansion of industrial applications of oxides. Herein, we demonstrate that combinatorial Al–Gd alloys covering 1.0 to 10.0 at.% Gd can be oxidized into ultra-thin anodic films of controlled thickness through a selection of electrolyte based on thermodynamics (phosphate buffer with a pH of 8.20). We propose that growth of anodic films on alloys at high efficiency is possible if Gibbs free energy minimization criteria would be systematically contemplate. Graphical abstract


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