Boosting CO2 electroreduction over layered zeolitic imidazolate frameworks decorated with Ag2O nanoparticles

2017 ◽  
Vol 5 (36) ◽  
pp. 19371-19377 ◽  
Author(s):  
Xiaole Jiang ◽  
Haihua Wu ◽  
Sujie Chang ◽  
Rui Si ◽  
Shu Miao ◽  
...  
Keyword(s):  
Composite Material ◽  
Current Density ◽  
Zeolitic Imidazolate Frameworks ◽  
Zeolitic Imidazolate Framework ◽  
Faradaic Efficiency ◽  
Co2 Electroreduction ◽  
Ag2o Nanoparticles

The Ag2O/layered zeolitic imidazolate framework (ZIF) composite material shows much higher CO faradaic efficiency and current density than the layered ZIF or Ag/C alone towards CO2 electroreduction.

Spontaneously Sn Doped Bi/BiOx Core–shell Nanowires Toward High-Performance CO2 Electroreduction to Formate

2021 ◽  
Author(s):  
Yang Zhao ◽  
Xunlin Liu ◽  
Zhixiao Liu ◽  
Xin Lin ◽  
Jiao Lan ◽  
...  
Keyword(s):  
Current Density ◽  
Hybrid Composites ◽  
Value Added ◽  
Gas Diffusion ◽  
Grand Challenge ◽  
Faradaic Efficiency ◽  
Electrochemical Co2 Reduction ◽  
Co2 Electroreduction ◽  
Metal Metal

Abstract Electrochemical CO2 reduction to formate using renewable electricity provides a promising strategy to product value-added carbon-based fuels and feedstocks. However, it still remains a grand challenge to further reduce the cathodic potentials and increase current density for the large-scale practical applications of formate. Herein, we report that spontaneously Sn doped Bi/BiOx nanowires (denoted as Bi/Bi(Sn)Ox NWs) are prepared from electrochemical dealloying strategy. The Bi/Bi(Sn)Ox NWs exhibit impressive CO2 electroreduction activity to formate with a Faradaic efficiency (FE) > 92% from -0.5 to -0.9 V versus reversible hydrogen electrode (RHE), and achieve a current density of 301.4 mA cm-2 at -1.0 V vs. RHE under gas diffusion cell configuration. In-situ Raman spectroscopy and theory calculations reveal that the incorporation of Sn atoms into BiOx species modulates the electron states of Bi, allowing the *OCHO intermediate to favorably adsorb onto the reconstructed Bi(Sn)Ox surface while promotes formate generation by suppressing the competitive hydrogen evolution reaction. This work provides effective in-situ construction of the metal/metal oxide hybrid composites with heteroatom doping and offers insights in promoting practical CO2 conversion technology.

scholarly journals Double sulfur vacancies by lithium tuning enhance CO2 electroreduction to n-propanol

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Chen Peng ◽  
Gan Luo ◽  
Junbo Zhang ◽  
Menghuan Chen ◽  
Zhiqiang Wang ◽  
...  
Keyword(s):  
Anion Vacancy ◽  
High Energy ◽  
Hydrogen Electrode ◽  
Cycle Number ◽  
Faradaic Efficiency ◽  
Flow Cells ◽  
Forming Mechanism ◽  
Co2 Electroreduction ◽  
Tuning Strategy ◽  
Partial Current

AbstractElectrochemical CO2 reduction can produce valuable products with high energy densities but the process is plagued by poor selectivities and low yields. Propanol represents a challenging product to obtain due to the complicated C3 forming mechanism that requires both stabilization of *C2 intermediates and subsequent C1–C2 coupling. Herein, density function theory calculations revealed that double sulfur vacancies formed on hexagonal copper sulfide can feature as efficient electrocatalytic centers for stabilizing both CO* and OCCO* dimer, and further CO–OCCO coupling to form C3 species, which cannot be realized on CuS with single or no sulfur vacancies. The double sulfur vacancies were then experimentally synthesized by an electrochemical lithium tuning strategy, during which the density of sulfur vacancies was well-tuned by the charge/discharge cycle number. The double sulfur vacancy-rich CuS catalyst exhibited a Faradaic efficiency toward n-propanol of 15.4 ± 1% at −1.05 V versus reversible hydrogen electrode in H-cells, and a high partial current density of 9.9 mA cm−2 at −0.85 V in flow-cells, comparable to the best reported electrochemical CO2 reduction toward n-propanol. Our work suggests an attractive approach to create anion vacancy pairs as catalytic centers for multi-carbon-products.

scholarly journals CuZnAl-Oxide Nanopyramidal Mesoporous Materials for the Electrocatalytic CO2 Reduction to Syngas: Tuning of H2/CO Ratio

Nanomaterials ◽  
2021 ◽  
Vol 11 (11) ◽  
pp. 3052
Author(s):  
Hilmar Guzmán ◽  
Daniela Roldán ◽  
Adriano Sacco ◽  
Micaela Castellino ◽  
Marco Fontana ◽  
...  
Keyword(s):  
Noble Metals ◽  
Co2 Reduction ◽  
Reduction Process ◽  
Mesoporous Structure ◽  
Catalytic Performance ◽  
H2 Production ◽  
Ambient Conditions ◽  
Transfer Resistance ◽  
Faradaic Efficiency ◽  
Co2 Electroreduction

Inspired by the knowledge of the thermocatalytic CO2 reduction process, novel nanocrystalline CuZnAl-oxide based catalysts with pyramidal mesoporous structures are here proposed for the CO2 electrochemical reduction under ambient conditions. The XPS analyses revealed that the co-presence of ZnO and Al2O3 into the Cu-based catalyst stabilize the CuO crystalline structure and introduce basic sites on the ternary as-synthesized catalyst. In contrast, the as-prepared CuZn- and Cu-based materials contain a higher amount of superficial Cu0 and Cu1+ species. The CuZnAl-catalyst exhibited enhanced catalytic performance for the CO and H2 production, reaching a Faradaic efficiency (FE) towards syngas of almost 95% at −0.89 V vs. RHE and a remarkable current density of up to 90 mA cm−2 for the CO2 reduction at −2.4 V vs. RHE. The physico-chemical characterizations confirmed that the pyramidal mesoporous structure of this material, which is constituted by a high pore volume and small CuO crystals, plays a fundamental role in its low diffusional mass-transfer resistance. The CO-productivity on the CuZnAl-catalyst increased at more negative applied potentials, leading to the production of syngas with a tunable H2/CO ratio (from 2 to 7), depending on the applied potential. These results pave the way to substitute state-of-the-art noble metals (e.g., Ag, Au) with this abundant and cost-effective catalyst to produce syngas. Moreover, the post-reaction analyses demonstrated the stabilization of Cu2O species, avoiding its complete reduction to Cu0 under the CO2 electroreduction conditions.

Zeolitic imidazolate framework-8 coated Fe3O4@SiO2 composites for magnetic solid-phase extraction of bisphenols

2020 ◽  
Vol 44 (14) ◽  
pp. 5324-5332 ◽  
Author(s):  
Jinfei Liu ◽  
Huijiao Qiu ◽  
Fei Zhang ◽  
Yan Li
Keyword(s):  
Composite Material ◽  
Solid Phase Extraction ◽  
Solid Phase ◽  
Magnetic Solid Phase Extraction ◽  
Magnetic Composite ◽  
Phase Extraction ◽  
Zeolitic Imidazolate Framework ◽  
Magnetic Solid ◽  
Plastic Products

A new magnetic composite material ZIF-8 coated Fe3O4@SiO2 was employed for preconcentration and detection of trace BPs in water and plastic products.

scholarly journals Tracking structural evolution: operando regenerative CeOx/Bi interface structure for high-performance CO2 electroreduction

2020 ◽  
Author(s):  
Ruichao Pang ◽  
Pengfei Tian ◽  
Hongliang Jiang ◽  
Minghui Zhu ◽  
Xiaozhi Su ◽  
...  
Keyword(s):  
High Performance ◽  
Density Functional ◽  
Structural Evolution ◽  
Density Functional Theory Calculations ◽  
Active Phase ◽  
Interface Structure ◽  
Operating Conditions ◽  
Faradaic Efficiency ◽  
Co2 Electroreduction ◽  
Water Activation

Abstract Unveiling the structural evolution and working mechanism of catalysts under realistic operating conditions is crucial for the design of efficient electrocatalysts for CO2 electroreduction, yet remains highly challenging. Here, by virtue of operando structural measurements at multiscale levels, it is identified under CO2 electroreduction conditions that an as-prepared CeO2/BiOCl precatalyst gradually evolves into CeOx/Bi interface structure with enriched Ce3+ species, which serves as the real catalytically active phase. The derived CeOx/Bi interface structure compared to pure Bi counterpart delivers substantially enhanced performance with a formate Faradaic efficiency approaching 90% for 24 hours in a wide potential window. The formate Faradaic efficiency can be further increased by using isotope D2O instead of H2O. Density functional theory calculations suggest that the regenerative CeOx/Bi interfacial sites can not only promote water activation to increase local *H species for CO2 protonation appropriately, but also stabilize the key intermediate *OCHO in formate pathway.

scholarly journals Zeolitic imidazolate framework (ZIF)-derived porous carbon materials for supercapacitors: an overview

RSC Advances ◽  
2020 ◽  
Vol 10 (71) ◽  
pp. 43733-43750
Author(s):  
Rabia Ahmad ◽  
Usman Ali Khan ◽  
Naseem Iqbal ◽  
Tayyaba Noor
Keyword(s):  
Porous Carbon ◽  
Carbon Materials ◽  
Synthetic Methods ◽  
Zeolitic Imidazolate Frameworks ◽  
Zeolitic Imidazolate Framework ◽  
Porous Carbon Materials

The present analysis focuses on the synthetic methods used for the application of supercapacitors with various mysterious architectures derived from zeolitic imidazolate frameworks (ZIFs).

scholarly journals FeNC catalysts for CO2 electroreduction to CO: effect of nanostructured carbon supports

2019 ◽  
Vol 3 (7) ◽  
pp. 1833-1840 ◽  
Author(s):  
Dilan Karapinar ◽  
Ngoc-Huan Tran ◽  
Domitille Giaume ◽  
Nastaran Ranjbar ◽  
Frédéric Jaouen ◽  
...  
Keyword(s):  
Carbon Nanofibers ◽  
Current Density ◽  
Carbon Materials ◽  
Nanostructured Carbon ◽  
Carbon Supports ◽  
Nitrogen Doped ◽  
Co2 Electroreduction ◽  
Nitrogen Doped Carbon

Iron- and nitrogen-doped carbon materials (FeNC) are excellent catalysts for CO2 electroreduction to CO. Current density and selectivity can be significantly improved by mixing FeNC with carbon materials such as carbon nanofibers.

scholarly journals A Universal Principle to Accurately Synthesize Atomically Dispersed Metal–N4 Sites for CO2 Electroreduction

2020 ◽  
Vol 12 (1) ◽  
Author(s):  
Wanzhen Zheng ◽  
Feng Chen ◽  
Qi Zeng ◽  
Zhongjian Li ◽  
Bin Yang ◽  
...  
Keyword(s):  
Metal Atom ◽  
Peak Power ◽  
Electric Energy ◽  
Energy Output ◽  
Central Metal ◽  
Faradaic Efficiency ◽  
Onset Potential ◽  
Co Conversion ◽  
Co2 Electroreduction ◽  
Specific Selectivity

AbstractAtomically dispersed metal–nitrogen sites-anchored carbon materials have been developed as effective catalysts for CO2 electroreduction (CO2ER), but they still suffer from the imprecisely control of type and coordination number of N atoms bonded with central metal. Herein, we develop a family of single metal atom bonded by N atoms anchored on carbons (SAs–M–N–C, M = Fe, Co, Ni, Cu) for CO2ER, which composed of accurate pyrrole-type M–N4 structures with isolated metal atom coordinated by four pyrrolic N atoms. Benefitting from atomically coordinated environment and specific selectivity of M–N4 centers, SAs–Ni–N–C exhibits superior CO2ER performance with onset potential of − 0.3 V, CO Faradaic efficiency (F.E.) of 98.5% at − 0.7 V, along with low Tafel slope of 115 mV dec−1 and superior stability of 50 h, exceeding all the previously reported M–N–C electrocatalysts for CO2-to-CO conversion. Experimental results manifest that the different intrinsic activities of M–N4 structures in SAs–M–N–C result in the corresponding sequence of Ni > Fe > Cu > Co for CO2ER performance. An integrated Zn–CO2 battery with Zn foil and SAs–Ni–N–C is constructed to simultaneously achieve CO2-to-CO conversion and electric energy output, which delivers a peak power density of 1.4 mW cm−2 and maximum CO F.E. of 93.3%.

Electrocatalytic reduction of CO2to CO with 100% faradaic efficiency by using pyrolyzed zeolitic imidazolate frameworks supported on carbon nanotube networks

2017 ◽  
Vol 5 (47) ◽  
pp. 24867-24873 ◽  
Author(s):  
Ying Guo ◽  
Huijuan Yang ◽  
Xin Zhou ◽  
Kunlong Liu ◽  
Chao Zhang ◽  
...  
Keyword(s):  
Carbon Nanotube ◽  
Electrochemical Reduction ◽  
Electrocatalytic Reduction ◽  
Zeolitic Imidazolate Frameworks ◽  
Faradaic Efficiency ◽  
Carbon Nanotube Networks

100% faradaic efficiency is achieved in electrochemical reduction of CO2to COviacoupling between ZIFs and CNTs.

scholarly journals Low-Overpotential Electrochemical Reduction of CO2 to Formic Acid on Surface-Modified Doped Tin Oxide Pellets

2019 ◽  
Author(s):  
Emmanuel Abdul ◽  
Jason Pitts ◽  
Deepak Rajput ◽  
Shankar Rananavare
Keyword(s):  
Formic Acid ◽  
Electrochemical Reduction ◽  
Current Density ◽  
Tin Oxide ◽  
Aqueous Media ◽  
Oxide Nanoparticles ◽  
Faradaic Efficiency ◽  
Electrode Potentials ◽  
Tin Oxide Nanoparticles ◽  
Reduction Of Co2

Gas sensors fabricated with antimony doped tin oxide (ATO) nanomaterials exhibit remarkable sensitivity for detecting oxidizing and reducing gases. This study highlights the enhanced selectivity and stability of the porous ATO nanomaterial electrode made for electrochemical reduction of CO2 in aqueous media. During electrochemical reduction, these electrodes prepared from compressed powders tend to crumble within a few hours in aqueous media. To overcome this electrode disintegration effect, we modified the surface of the doped tin-Oxide nanoparticles with Nafion and a dipodal silane (1,2-Bis(triethoxysilyl)ethane). The electrode characterization studies include Cyclic Voltammetry (CV), and Electrochemical Impedance Spectroscopy (EIS). Scanning electron microscopic investigation of electrode surface morphology and roughness before and after electrochemical CO2 reduction for derivatized and underivatized electrode revealed lower surface roughness for former than the latter.The derivatized electrodes allowed CO2 electrochemical reduction at low overpotentials and high current density without any electrode crumbling over more than 24 hours of continuous operation. Formate/formic acid and methanol were the major products of reduction at electrode potentials ranging from -0.4 to -1.0V vs. RHE in the CO2 saturated 0.1M KHCO3 electrolyte. Higher current density and Faradaic Efficiency of formic acid was observed when compared to planar tin electrode materials and tin oxide nanoparticles deposited on FTO glass.

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