scholarly journals Boosting selective nitrogen reduction to ammonia on electron-deficient copper nanoparticles

2019 ◽  
Vol 10 (1) ◽  
Author(s):  
Yun-Xiao Lin ◽  
Shi-Nan Zhang ◽  
Zhong-Hua Xue ◽  
Jun-Jun Zhang ◽  
Hui Su ◽  
...  
Keyword(s):  
Rational Design ◽  
Reduction Reaction ◽  
Reaction Process ◽  
Cu Nanoparticles ◽  
Ambient Conditions ◽  
Depletion Effect ◽  
Aqueous Conditions ◽  
Electron Deficiency ◽  
Near Future ◽  
Insight Into

Abstract Production of ammonia is currently realized by the Haber–Bosch process, while electrochemical N2 fixation under ambient conditions is recognized as a promising green substitution in the near future. A lack of efficient electrocatalysts remains the primary hurdle for the initiation of potential electrocatalytic synthesis of ammonia. For cheaper metals, such as copper, limited progress has been made to date. In this work, we boost the N2 reduction reaction catalytic activity of Cu nanoparticles, which originally exhibited negligible N2 reduction reaction activity, via a local electron depletion effect. The electron-deficient Cu nanoparticles are brought in a Schottky rectifying contact with a polyimide support which retards the hydrogen evolution reaction process in basic electrolytes and facilitates the electrochemical N2 reduction reaction process under ambient aqueous conditions. This strategy of inducing electron deficiency provides new insight into the rational design of inexpensive N2 reduction reaction catalysts with high selectivity and activity.

Rational design of nanocatalysts for ambient ammonia electrosynthesis

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Limin Wu ◽  
Weiwei Guo ◽  
Xiaofu Sun ◽  
Buxing Han
Keyword(s):  
Rational Design ◽  
Research Area ◽  
Reduction Reaction ◽  
Single Atom ◽  
Future Research ◽  
Design Strategies ◽  
Ambient Conditions ◽  
Renewable Electricity ◽  
Huge Amount ◽  
Nano Structure

Abstract Ammonia (NH3) is one of the key commercial chemicals and carbon-free energy carriers. It is mainly made by Haber-Bosch process under high temperature and high pressure, which consumes huge amount of energy and releases large amounts of CO2. Developing sustainable approaches to its production is of great importance. Powered by a renewable electricity source, electrochemical N2 reduction reaction (NRR) and nitrate reduction reaction (NITRR) are potential routes to synthesize NH3 under ambient conditions. This review summarizes major recent advances in the NRR and NITRR, especially for several years. Some fundamentals for NRR and NITRR are first introduced. Afterward, the design strategies of nanocatalysts are discussed, mainly focusing on nano-structure construction/nanoconfinement, doping/defects engineering and single-atom engineering. Finally, the critical challenges remaining in this research area and promising directions for future research are discussed.

Rational design of boron contained co-doped graphene as high efficient electro-catalysts for nitrogen reduction reaction

2021 ◽  
Author(s):  
Wencheng Ouyang ◽  
Qiuming Zhi ◽  
LeLe Gong ◽  
Hao Sun ◽  
Minghui Liu ◽  
...  
Keyword(s):  
Nitrogen Fixation ◽  
Renewable Energy ◽  
Rational Design ◽  
Reduction Reaction ◽  
Ammonia Production ◽  
Ambient Conditions ◽  
Nitrogen Reduction ◽  
High Efficient ◽  
Doped Graphene ◽  
Co Doped

Electrocatalytic nitrogen reduction reaction (NRR) under ambient conditions has been proposed as a sustainable alternative for nitrogen fixation and ammonia production in environment and renewable energy fields. Carbon-based materials have...

scholarly journals Mo-doped boron nitride monolayer as a promising single-atom electrocatalyst for CO2 conversion

2019 ◽  
Vol 10 ◽  
pp. 540-548 ◽  
Author(s):  
Qianyi Cui ◽  
Gangqiang Qin ◽  
Weihua Wang ◽  
Lixiang Sun ◽  
Aijun Du ◽  
...  
Keyword(s):  
Boron Nitride ◽  
Density Functional ◽  
Experimental Studies ◽  
Catalytic Performance ◽  
Reduction Reaction ◽  
Single Atom ◽  
Ambient Conditions ◽  
Functional Theory ◽  
Earth Abundant ◽  
Insight Into

The design of new, efficient catalysts for the conversion of CO2 to useful fuels under mild conditions is urgent in order to reduce greenhouse gas emissions and alleviate the energy crisis. In this work, a series of transition metals (TMs), including Sc to Zn, Mo, Ru, Rh, Pd and Ag, supported on a boron nitride (BN) monolayer with boron vacancies, were investigated as electrocatalysts for the CO2 reduction reaction (CRR) using comprehensive density functional theory (DFT) calculations. The results demonstrate that a single-Mo-atom-doped boron nitride (Mo-doped BN) monolayer possesses excellent performance for converting CO2 to CH4 with a relatively low limiting potential of −0.45 V, which is lower than most catalysts for the selective production of CH4 as found in both theoretical and experimental studies. In addition, the formation of OCHO on the Mo-doped BN monolayer in the early hydrogenation steps is found to be spontaneous, which is distinct from the conventional catalysts. Mo, as a non-noble element, presents excellent catalytic performance with coordination to the BN monolayer, and is thus a promising transition metal for catalyzing CRR. This work not only provides insight into the mechanism of CRR on the single-atom catalyst (Mo-doped BN monolayer) at the atomic level, but also offers guidance in the search for appropriate earth-abundant TMs as electrochemical catalysts for the efficient conversion of CO2 to useful fuels under ambient conditions.

Ordered Intermetallic Nanoparticles with High Catalytic Activity Prepared by an Electrochemically Induced Phase Transformation

2019 ◽  
Author(s):  
Du Sun ◽  
yunfei wang ◽  
Kenneth Livi ◽  
chuhong wang ◽  
ruichun luo ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Diffusion Mechanism ◽  
Reduction Reaction ◽  
Atomic Scale ◽  
High Catalytic Activity ◽  
Ambient Conditions ◽  
Magnetic Devices ◽  
Disordered Alloys ◽  
Ordered Intermetallic ◽  
Intermetallic Nanoparticles

<div> <p>The synthesis of alloys with long range atomic scale ordering (ordered intermetallics) is an emerging field of nanochemistry. Ordered intermetallic nanoparticles are useful for a wide variety of applications such as catalysis, superconductors, and magnetic devices. However, the preparation of nanostructured ordered intermetallics is challenging in comparison to disordered alloys, hindering progress in materials development. We report a process for converting colloidally synthesized ordered intermetallic PdBi<sub>2</sub> to ordered intermetallic Pd<sub>3</sub>Bi nanoparticles under ambient conditions by an electrochemically induced phase transition. The low melting point of PdBi<sub>2</sub> corresponds to low vacancy formation energies which enables the facile removal of the Bi from the surface, while simultaneously enabling interdiffusion of the constituent atoms via a vacancy diffusion mechanism under ambient conditions. The resulting phase-converted ordered intermetallic Pd<sub>3</sub>Bi exhibits 11x and 3.5x higher mass activty and high methanol tolerance for the oxygen reduction reaction compared to Pt/C and Pd/C, respectively,which is the highest reported for a Pd-based catalyst, to the best of our knowledge. These results establish a key development in the synthesis of noble metal rich ordered intermetallic phases with high catalytic activity, and sets forth guidelines for the design of ordered intermetallic compounds under ambient conditions.</p> </div>

High-Entropy Alloys as Catalysts for the CO2 and CO Reduction Reactions

2019 ◽  
Author(s):  
Jack Pedersen ◽  
Thomas Batchelor ◽  
Alexander Bagger ◽  
Jan Rossmeisl
Keyword(s):  
Density Functional ◽  
Rational Design ◽  
Hydrogen Adsorption ◽  
Co Adsorption ◽  
Reduction Reaction ◽  
Supervised Machine Learning ◽  
High Entropy Alloys ◽  
High Entropy ◽  
Co Reduction ◽  
Disordered Alloy

Using the high-entropy alloys (HEAs) CoCuGaNiZn and AgAuCuPdPt as starting points we provide a framework for tuning the composition of disordered multi-metallic alloys to control the selectivity and activity of the reduction of carbon dioxide (CO2) to highly reduced compounds. By combining density functional theory (DFT) with supervised machine learning we predicted the CO and hydrogen (H) adsorption energies of all surface sites on the (111) surface of the two HEAs. This allowed an optimization for the HEA compositions with increased likelihood for sites with weak hydrogen adsorption{to suppress the formation of molecular hydrogen (H2) and with strong CO adsorption to favor the reduction of CO. This led to the discovery of several disordered alloy catalyst candidates for which selectivity towards highly reduced carbon compounds is expected, as well as insights into the rational design of disordered alloy catalysts for the CO2 and CO reduction reaction.

scholarly journals Defect and Doping Co-Engineered Non-Metal Nanocarbon ORR Electrocatalyst

2021 ◽  
Vol 13 (1) ◽  
Author(s):  
Jian Zhang ◽  
Jingjing Zhang ◽  
Feng He ◽  
Yijun Chen ◽  
Jiawei Zhu ◽  
...  
Keyword(s):  
Rational Design ◽  
Low Cost ◽  
Reduction Reaction ◽  
Defect Engineering ◽  
Heteroatom Doping ◽  
Competitive Activity ◽  
Design And Manufacturing ◽  
Earth Abundant ◽  
Induced Defects ◽  
Carbon Based

AbstractExploring low-cost and earth-abundant oxygen reduction reaction (ORR) electrocatalyst is essential for fuel cells and metal–air batteries. Among them, non-metal nanocarbon with multiple advantages of low cost, abundance, high conductivity, good durability, and competitive activity has attracted intense interest in recent years. The enhanced ORR activities of the nanocarbons are normally thought to originate from heteroatom (e.g., N, B, P, or S) doping or various induced defects. However, in practice, carbon-based materials usually contain both dopants and defects. In this regard, in terms of the co-engineering of heteroatom doping and defect inducing, we present an overview of recent advances in developing non-metal carbon-based electrocatalysts for the ORR. The characteristics, ORR performance, and the related mechanism of these functionalized nanocarbons by heteroatom doping, defect inducing, and in particular their synergistic promotion effect are emphatically analyzed and discussed. Finally, the current issues and perspectives in developing carbon-based electrocatalysts from both of heteroatom doping and defect engineering are proposed. This review will be beneficial for the rational design and manufacturing of highly efficient carbon-based materials for electrocatalysis.

scholarly journals Phase-selective active sites on ordered/disordered titanium dioxide enable exceptional photocatalytic ammonia synthesis

2021 ◽  
Author(s):  
Jinsun Lee ◽  
Xinghui Liu ◽  
Ashwani Kumar ◽  
Yosep Hwang ◽  
Eunji Lee ◽  
...  
Keyword(s):  
Titanium Dioxide ◽  
Active Sites ◽  
Rational Design ◽  
Ammonia Synthesis ◽  
Reduction Reaction ◽  
Band Structures ◽  
Electronic Band ◽  
Defect Sites ◽  
Electronic Band Structures ◽  
Reaction Routes

This work highlights the importance of a rational design for more energetically suitable nitrogen reduction reaction routes and mechanisms by regulating the electronic band structures with phase-selective defect sites.

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