scholarly journals Moving Mountains: Reshaping the Activity Volcano of Electrocatalysis with Fluxional Subnano Clusters

2021 ◽  
Author(s):  
Zisheng Zhang ◽  
Borna Zandkarimi ◽  
Julen Munarriz ◽  
Claire Dickerson ◽  
Anastassia N. Alexandrova
Keyword(s):  
High Performance ◽  
Maximal Activity ◽  
Reduction Reaction ◽  
Catalyst Design ◽  
Linear Scaling ◽  
Energy Potential ◽  
Fundamental Limitations ◽  
Reaction Free Energy ◽  
Linear Reaction ◽  
Optimal Reaction

The activity volcano derived from Sabatier analysis provides intuitive guide for catalyst design, but it also imposes fundamental limitations on the maximal activity and the pool of high-performance elements. Here we show that the activity volcano for oxygen reduction reaction (ORR) can be shifted and reshaped in the subnano regime. The fluxional behavior of subnano clusters, in both isolated and graphite-supported forms, not only breaks the linear scaling relationships but also causes an overall strengthening in adsorbate binding. The metals with optimal adsorbate binding in the bulk form (Pt/Pd) thus suffer over-binding issues, while the metals that under-bind in the bulk form (Ag/Au) gain optimal reaction energetics. In addition, the potential-dependence of isomer energies differ, causing non-linear reaction free energy-potential relations and enabling population-tuning of specific isomers, thereby surpassing the apex of the activity volcano. The shift of the volcano that puts under-binding elements closer to the top is likely general in fluxional cluster catalysis, and can be used for cluster catalyst design.

An innovative catalyst design as an efficient electro catalyst and its applications in quantum-dot sensitized solar cells and the oxygen reduction reaction for fuel cells

2017 ◽  
Vol 41 (5) ◽  
pp. 2098-2111 ◽  
Author(s):  
Ikkurthi Kanaka Durga ◽  
S. Srinivasa Rao ◽  
Dinah Punnoose ◽  
Nagabhushanam Kundakarla ◽  
Chebrolu Venkata Tulasivarma ◽  
...  
Keyword(s):  
Solar Cells ◽  
Fuel Cells ◽  
Quantum Dot ◽  
Oxygen Reduction Reaction ◽  
Oxygen Reduction ◽  
High Performance ◽  
Reduction Reaction ◽  
Catalyst Design ◽  
Ni Foam ◽  
Sensitized Solar Cells

Highly-efficient Co90%Ni10% catalytic nanostructures on FTO and Ni-foam show high performance in QDSSCs and fuel cells.

scholarly journals Efficient Catalytic Conversion of Polysulfides by Biomimetic Design of “Branch-Leaf” Electrode for High-Energy Sodium–Sulfur Batteries

2021 ◽  
Vol 13 (1) ◽  
Author(s):  
Wenyan Du ◽  
Kangqi Shen ◽  
Yuruo Qi ◽  
Wei Gao ◽  
Mengli Tao ◽  
...  
Keyword(s):  
Active Sites ◽  
High Performance ◽  
Electrochemical Reaction ◽  
Molecular Layer ◽  
Specific Capacity ◽  
High Energy ◽  
Reduction Reaction ◽  
Biomimetic Design ◽  
Co Nanoparticles ◽  
Sodium Sulfur

AbstractRechargeable room temperature sodium–sulfur (RT Na–S) batteries are seriously limited by low sulfur utilization and sluggish electrochemical reaction activity of polysulfide intermediates. Herein, a 3D “branch-leaf” biomimetic design proposed for high performance Na–S batteries, where the leaves constructed from Co nanoparticles on carbon nanofibers (CNF) are fully to expose the active sites of Co. The CNF network acts as conductive “branches” to ensure adequate electron and electrolyte supply for the Co leaves. As an effective electrocatalytic battery system, the 3D “branch-leaf” conductive network with abundant active sites and voids can effectively trap polysulfides and provide plentiful electron/ions pathways for electrochemical reaction. DFT calculation reveals that the Co nanoparticles can induce the formation of a unique Co–S–Na molecular layer on the Co surface, which can enable a fast reduction reaction of the polysulfides. Therefore, the prepared “branch-leaf” CNF-L@Co/S electrode exhibits a high initial specific capacity of 1201 mAh g−1 at 0.1 C and superior rate performance.

scholarly journals Quasi-graphitic carbon shell-induced Cu confinement promotes electrocatalytic CO2 reduction toward C2+ products

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Ji-Yong Kim ◽  
Deokgi Hong ◽  
Jae-Chan Lee ◽  
Hyoung Gyun Kim ◽  
Sungwoo Lee ◽  
...  
Keyword(s):  
High Efficiency ◽  
Co2 Reduction ◽  
Value Added ◽  
Material Design ◽  
Catalyst System ◽  
Critical Issue ◽  
Reduction Reaction ◽  
Catalyst Design ◽  
Design Strategies ◽  
Faradaic Efficiency

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.

Tunable mesoporous manganese oxide for high performance oxygen reduction and evolution reactions

2016 ◽  
Vol 4 (2) ◽  
pp. 620-631 ◽  
Author(s):  
Islam M. Mosa ◽  
Sourav Biswas ◽  
Abdelhamid M. El-Sawy ◽  
Venkatesh Botu ◽  
Curtis Guild ◽  
...  
Keyword(s):  
Oxygen Reduction Reaction ◽  
Manganese Oxide ◽  
Oxygen Reduction ◽  
Oxygen Evolution ◽  
Oxygen Evolution Reaction ◽  
High Performance ◽  
Reduction Reaction ◽  
Noble Metal Catalysts ◽  
Highly Active ◽  
State Of Art

Understanding the origin of manganese oxide activity for oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) is a key step towards rationally designing of highly active catalysts capable of competing with the widely used, state-of-art noble metal catalysts.

Ferrocene-based porous organic polymer derived high-performance electrocatalysts for oxygen reduction

2017 ◽  
Vol 5 (42) ◽  
pp. 22163-22169 ◽  
Author(s):  
Baolong Zhou ◽  
Liangzhen Liu ◽  
Pingwei Cai ◽  
Guang Zeng ◽  
Xiaoqiang Li ◽  
...  
Keyword(s):  
Schiff Base ◽  
Catalytic Activity ◽  
Oxygen Reduction Reaction ◽  
Oxygen Reduction ◽  
Porous Carbon ◽  
High Performance ◽  
Reduction Reaction ◽  
Organic Polymer ◽  
Porous Organic Polymers ◽  
Porous Organic Polymer

Two nitrogen-rich porous organic polymers (POPs) were prepared via Schiff base chemistry. Carbonization of these POPs results in porous carbon nanohybrids which exhibit excellent catalytic activity toward the oxygen reduction reaction (ORR).

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