scholarly journals Marine Algae-Derived Porous Carbons as Robust Electrocatalysts for ORR

Catalysts ◽  
2019 ◽  
Vol 9 (9) ◽  
pp. 730 ◽  
Author(s):  
Li ◽  
Liu ◽  
Wang ◽  
Yang ◽  
Chen ◽  
...  
Keyword(s):  
Fuel Cell ◽  
Marine Algae ◽  
Value Added ◽  
Catalytic Performance ◽  
Reduction Reaction ◽  
Activation Process ◽  
Porous Carbons ◽  
Ambient Conditions ◽  
Innovative Strategy ◽  
Electrochemical Catalyst

Large quantities of marine algae are annually produced, and have been disposed or burned as solid waste. In this work, porous carbons were prepared from three kinds of marine algae (Enteromorpha, Laminaria, and Chlorella) by a two-step activation process. The as-prepared carbon materials were doped with cobalt (Co) and applied as catalysts for oxygen reduction reaction (ORR). Our results demonstrated that Co-doped porous carbon prepared from Enteromorpha sp. (denoted by Co-PKEC) displayed excellent catalytic performance for ORR. Co-PKEC obtained a half-wave potential of 0.810 V (vs. RHE) and a maximum current density of 4.41 mA/cm2, which was comparable to the commercial 10% Pt/C catalyst (E1/2 = 0.815 V, Jd = 4.40 mA/cm2). In addition, Co-PKEC had excellent long-term stability and methanol resistance. The catalytic ability of Co-PKEC was evaluated in a one-chamber glucose fuel cell. The maximum power density of the fuel cell equipped with the Co-PKEC cathode was 33.53 W/m2 under ambient conditions, which was higher than that of the fuel cell with a 10% Pt/C cathode. This study not only demonstrated an easy-to-implement approach to prepare robust electrochemical catalyst from marine algal biomass, but also provided an innovative strategy for simultaneous waste remediation and value-added material production.

Non Precious Metal Catalysts: A Fuel Cell and ORR Study of Thermally Synthesized Nickel and Platinum Mixed Nickel Nanotubes for PEMFC

2021 ◽  
Vol 875 ◽  
pp. 193-199
Author(s):  
Ahmad Shahbaz ◽  
Ali Afaf ◽  
Nawaz Tahir ◽  
Ullah Abid ◽  
Saher Saim
Keyword(s):  
Fuel Cell ◽  
Proton Exchange Membrane ◽  
Rotating Disk ◽  
Platinum Group Metal ◽  
Catalytic Performance ◽  
Reduction Reaction ◽  
Proton Exchange ◽  
Rotating Disk Electrode ◽  
Highly Active ◽  
Precious Metal Catalysts

A highly active Platinum Group Metal (PGM) and non-PGM electrocatalysts with thermally extruded nanotubes have been prepared for Proton Exchange Membrane (PEM) fuel cell by sintering Nickel zeolitic imidazole framework (Ni-ZIF). Preeminent electro-catalytic activities have been observed through single fuel cell tests and rotating disk electrode (RDE). This study involves the comparison of Oxygen Reduction Reaction (ORR) activities and fuel cell (FC) test station performance of two catalyst Nickel and Platinum mixed Nickel nanotubes (Ni NT, Ni/Pt NT) respectively. The acidic cells with corresponding Ni and Ni/Pt catalysts delivers peak power densities of 325 mWcm-2 and 455 mWcm-2 at 75 °C inside fuel cell. Our results indicate that, the synthesized Nickel nanotubes has profound effect on catalytic performance of both PGM and non-PGM electro catalysts.

Ultralow-loading platinum-cobalt fuel cell catalysts derived from imidazolate frameworks

Science ◽  
2018 ◽  
Vol 362 (6420) ◽  
pp. 1276-1281 ◽  
Author(s):  
Lina Chong ◽  
Jianguo Wen ◽  
Joseph Kubal ◽  
Fatih G. Sen ◽  
Jianxin Zou ◽  
...  
Keyword(s):  
Fuel Cell ◽  
Platinum Group Metal ◽  
Catalytic Performance ◽  
Reduction Reaction ◽  
Zeolitic Imidazolate Frameworks ◽  
Shell Nanoparticles ◽  
Fuel Cell Performance ◽  
Synergistic Catalysis ◽  
Highly Active ◽  
Core Shell Nanoparticles

Achieving high catalytic performance with the lowest possible amount of platinum is critical for fuel cell cost reduction. Here we describe a method of preparing highly active yet stable electrocatalysts containing ultralow-loading platinum content by using cobalt or bimetallic cobalt and zinc zeolitic imidazolate frameworks as precursors. Synergistic catalysis between strained platinum-cobalt core-shell nanoparticles over a platinum-group metal (PGM)–free catalytic substrate led to excellent fuel cell performance under 1 atmosphere of O2 or air at both high-voltage and high-current domains. Two catalysts achieved oxygen reduction reaction (ORR) mass activities of 1.08 amperes per milligram of platinum (A mgPt−1) and 1.77 A mgPt−1 and retained 64% and 15% of initial values after 30,000 voltage cycles in a fuel cell. Computational modeling reveals that the interaction between platinum-cobalt nanoparticles and PGM-free sites improves ORR activity and durability.

Fe–Nxmoiety-modified hierarchically porous carbons derived from porphyra for highly effective oxygen reduction reaction

2017 ◽  
Vol 5 (4) ◽  
pp. 1526-1532 ◽  
Author(s):  
Zhengping Zhang ◽  
Xinjin Gao ◽  
Meiling Dou ◽  
Jing Ji ◽  
Feng Wang
Keyword(s):  
Oxygen Reduction Reaction ◽  
Oxygen Reduction ◽  
Porous Carbon ◽  
Catalytic Performance ◽  
Reduction Reaction ◽  
Porous Carbons ◽  
Hierarchically Porous ◽  
Nitrogen Doped ◽  
Highly Effective ◽  
Excellent Catalytic Performance

Fe–Nxmoiety-modified nitrogen-doped hierarchically porous carbon, which is derived from porphyra, exhibits an excellent catalytic performance for oxygen reduction.

Monolayer graphitic germanium carbide (g-GeC): the promising cathode catalyst for fuel cell and lithium–oxygen battery applications

2018 ◽  
Vol 6 (5) ◽  
pp. 2212-2218 ◽  
Author(s):  
Yujin Ji ◽  
Huilong Dong ◽  
Tingjun Hou ◽  
Youyong Li
Keyword(s):  
Fuel Cells ◽  
Fuel Cell ◽  
Oxygen Reduction Reaction ◽  
Oxygen Reduction ◽  
Catalytic Performance ◽  
Reduction Reaction ◽  
Cathode Catalyst ◽  
Germanium Carbide ◽  
Lithium Oxygen Battery ◽  
Excellent Catalytic Performance

Monolayer g-GeC exhibits excellent catalytic performance for oxygen reduction reaction when used as a cathode catalyst in fuel cells and Li–O2 batteries.

scholarly journals Bismuth-Based Free-Standing Electrodes for Ambient-Condition Ammonia Production in Neutral Media

2020 ◽  
Vol 12 (1) ◽  
Author(s):  
Ying Sun ◽  
Zizhao Deng ◽  
Xi-Ming Song ◽  
Hui Li ◽  
Zihang Huang ◽  
...  
Keyword(s):  
Low Cost ◽  
Catalytic Performance ◽  
Reduction Reaction ◽  
Ambient Conditions ◽  
Free Standing ◽  
Hydrogen Electrode ◽  
Faradaic Efficiency ◽  
Long Term Stability ◽  
High Efficient ◽  
Neutral Media

AbstractElectrocatalytic nitrogen reduction reaction is a carbon-free and energy-saving strategy for efficient synthesis of ammonia under ambient conditions. Here, we report the synthesis of nanosized Bi2O3 particles grown on functionalized exfoliated graphene (Bi2O3/FEG) via a facile electrochemical deposition method. The obtained free-standing Bi2O3/FEG achieves a high Faradaic efficiency of 11.2% and a large NH3 yield of 4.21 ± 0.14 $$ \upmu{\text{g}}_{{{\text{NH}}_{3} }} $$ μ g NH 3  h−1 cm−2 at − 0.5 V versus reversible hydrogen electrode in 0.1 M Na2SO4, better than that in the strong acidic and basic media. Benefiting from its strong interaction of Bi 6p band with the N 2p orbitals, binder-free characteristic, and facile electron transfer, Bi2O3/FEG achieves superior catalytic performance and excellent long-term stability as compared with most of the previous reported catalysts. This study is significant to design low-cost, high-efficient Bi-based electrocatalysts for electrochemical ammonia synthesis.

scholarly journals Regulating kinetics and thermodynamics of electrochemical nitrogen reduction with metal single-atom catalysts in a pressurized electrolyser

2020 ◽  
Vol 117 (47) ◽  
pp. 29462-29468
Author(s):  
Haiyuan Zou ◽  
Weifeng Rong ◽  
Shuting Wei ◽  
Yongfei Ji ◽  
Lele Duan
Keyword(s):  
Driving Forces ◽  
Theoretical Calculations ◽  
Formation Rate ◽  
Reaction System ◽  
Value Added ◽  
Reduction Reaction ◽  
Single Atom ◽  
Ambient Conditions ◽  
Hydrogen Electrode ◽  
Nitrogen Reduction

Using renewable electricity to synthesize ammonia from nitrogen paves a sustainable route to making value-added chemicals but yet requires further advances in electrocatalyst development and device integration. By engineering both electrocatalyst and electrolyzer to simultaneously regulate chemical kinetics and thermodynamic driving forces of the electrocatalytic nitrogen reduction reaction (ENRR), we report herein stereoconfinement-induced densely populated metal single atoms (Rh, Ru, Co) on graphdiyne (GDY) matrix (formulated as M SA/GDY) and realized a boosted ENRR activity in a pressurized reaction system. Remarkably, under the pressurized environment, the hydrogen evolution reaction of M SA/GDY was effectively suppressed and the desired ENRR activity was strongly amplificated. As a result, the pressurized ENRR activity of Rh SA/GDY at 55 atm exhibited a record-high NH3formation rate of 74.15 μg h−1⋅cm−2, a Faraday efficiency of 20.36%, and a NH3partial current of 0.35 mA cm−2at −0.20 V versus reversible hydrogen electrode, which, respectively, displayed 7.3-, 4.9-, and 9.2-fold enhancements compared with those obtained under ambient conditions. Furthermore, a time-independent ammonia yield rate using purified15N2confirmed the concrete ammonia electroproduction. Theoretical calculations reveal that the driving force for the formation of end-on N2* on Rh SA/GDY increased by 9.62 kJ/mol under the pressurized conditions, facilitating the ENRR process. We envisage that the cooperative regulations of catalysts and electrochemical devices open up the possibilities for industrially viable electrochemical ammonia production.

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.

scholarly journals A study on improving the current density performances of CO2 electrolysers

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Yueyuan Gu ◽  
Jucai Wei ◽  
Xu Wu ◽  
Xiaoteng Liu
Keyword(s):  
Current Density ◽  
Value Added ◽  
Cell Voltage ◽  
Electrical Energy ◽  
Catalytic Performance ◽  
Gas Diffusion ◽  
Reduction Reaction ◽  
Cell Performance ◽  
Anion Exchange Membranes ◽  
Flow Cells

AbstractElectrochemical CO2 reduction reaction (CO2RR) technology can reduce CO2 emission with converting excess electrical energy to high-value-added chemicals, which however needs further improvement on the electrolyser cell performance. In this work, extensive factors were explored in continuous CO2 electrolysers. Gold, one of the benchmark materials for CO2RR to produce CO, was used as the catalyst. Electrolyser configurations and membrane types have significant influences on cell performance. Compact MEA-constructed gas-phase electrolyser showed better catalytic performance and lower energy consumption. The gas diffusion electrode with a 7:1 mass ratio of total-catalyst-to-polytetrafluoroethylene (PTFE) ionomer exhibited the best performance. At a low total cell voltage of 2.2 V, the partial current density of CO production achieved 196.8 mA cm−2, with 90.6% current efficiency and 60.4% energy efficiency for CO producing respectively. Higher CO selectivity can be achieved using anion exchange membranes, while higher selectivity for hydrogen and formate products can be achieved with cation exchange membranes. This research has pointed out a way on how to improve the CO2RR catalytic performance in flow cells, leaving aside the characteristics of the catalyst itself.

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