ORCID Profile
0000-0002-8108-0975
Current Organisation
Stanford University School of Engineering
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Publisher: Springer Science and Business Media LLC
Date: 18-12-2019
Publisher: Springer Science and Business Media LLC
Date: 11-11-2019
Publisher: Springer Science and Business Media LLC
Date: 16-12-2019
Publisher: American Chemical Society (ACS)
Date: 16-10-2023
Publisher: Royal Society of Chemistry (RSC)
Date: 2023
DOI: 10.1039/D2EY00046F
Abstract: In a direct carbonate electrolysis system, a CO 2 diffusion layer enabled the production of CO-rich syngas.
Publisher: Springer Science and Business Media LLC
Date: 07-06-2023
DOI: 10.1038/S41467-023-38935-2
Abstract: Renewable CH 4 produced from electrocatalytic CO 2 reduction is viewed as a sustainable and versatile energy carrier, compatible with existing infrastructure. However, conventional alkaline and neutral CO 2 -to-CH 4 systems suffer CO 2 loss to carbonates, and recovering the lost CO 2 requires input energy exceeding the heating value of the produced CH 4 . Here we pursue CH 4 -selective electrocatalysis in acidic conditions via a coordination method, stabilizing free Cu ions by bonding Cu with multidentate donor sites. We find that hexadentate donor sites in ethylenediaminetetraacetic acid enable the chelation of Cu ions, regulating Cu cluster size and forming Cu-N/O single sites that achieve high CH 4 selectivity in acidic conditions. We report a CH 4 Faradaic efficiency of 71% (at 100 mA cm −2 ) with % loss in total input CO 2 that results in an overall energy intensity (254 GJ/tonne CH 4 ), half that of existing electroproduction routes.
Publisher: Springer Science and Business Media LLC
Date: 23-07-2020
DOI: 10.1038/S41467-020-17499-5
Abstract: Multi-carbon alcohols such as ethanol are valued as fuels in view of their high energy density and ready transport. Unfortunately, the selectivity toward alcohols in CO 2 /CO electroreduction is diminished by ethylene production, especially when operating at high current densities ( mA cm −2 ). Here we report a metal doping approach to tune the adsorption of hydrogen at the copper surface and thereby promote alcohol production. Using density functional theory calculations, we screen a suite of transition metal dopants and find that incorporating Pd in Cu moderates hydrogen adsorption and assists the hydrogenation of C 2 intermediates, providing a means to favour alcohol production and suppress ethylene. We synthesize a Pd-doped Cu catalyst that achieves a Faradaic efficiency of 40% toward alcohols and a partial current density of 277 mA cm −2 from CO electroreduction. The activity exceeds that of prior reports by a factor of 2.
Publisher: Springer Science and Business Media LLC
Date: 09-02-2023
Publisher: American Association for the Advancement of Science (AAAS)
Date: 04-06-2021
Abstract: Electrochemical reduction of carbon dioxide (CO 2 ) is a promising means of converting this greenhouse gas into valuable fuels and chemicals. However, two competing reactions restrict the efficiency of this process. In base, much of the CO 2 is trapped as carbonate before reduction in acid, protons outpace CO 2 at catching electrons from the cathode. Huang et al. report that a high dose of potassium ions can help to solve the latter problem. By concentrating potassium ions at the electrode, high selectivity toward CO 2 reduction at high current in acid is possible, which the authors attribute to electrostatic stabilization of the desired adsorbates. Science , abg6582, this issue p. 1074
Publisher: Springer Science and Business Media LLC
Date: 03-12-2020
DOI: 10.1038/S41467-020-20004-7
Abstract: Electroreduction uses renewable energy to upgrade carbon dioxide to value-added chemicals and fuels. Renewable methane synthesized using such a route stands to be readily deployed using existing infrastructure for the distribution and utilization of natural gas. Here we design a suite of ligand-stabilized metal oxide clusters and find that these modulate carbon dioxide reduction pathways on a copper catalyst, enabling thereby a record activity for methane electroproduction. Density functional theory calculations show adsorbed hydrogen donation from clusters to copper active sites for the *CO hydrogenation pathway towards *CHO. We promote this effect via control over cluster size and composition and demonstrate the effect on metal oxides including cobalt(II), molybdenum(VI), tungsten(VI), nickel(II) and palladium(II) oxides. We report a carbon dioxide-to-methane faradaic efficiency of 60% at a partial current density to methane of 135 milli ere per square centimetre. We showcase operation over 18 h that retains a faradaic efficiency exceeding 55%.
Publisher: Springer Science and Business Media LLC
Date: 18-05-2021
DOI: 10.1038/S41467-021-23065-4
Abstract: The electrochemical conversion of CO 2 to methane provides a means to store intermittent renewable electricity in the form of a carbon-neutral hydrocarbon fuel that benefits from an established global distribution network. The stability and selectivity of reported approaches reside below technoeconomic-related requirements. Membrane electrode assembly-based reactors offer a known path to stability however, highly alkaline conditions on the cathode favour C-C coupling and multi-carbon products. In computational studies herein, we find that copper in a low coordination number favours methane even under highly alkaline conditions. Experimentally, we develop a carbon nanoparticle moderator strategy that confines a copper-complex catalyst when employed in a membrane electrode assembly. In-situ XAS measurements confirm that increased carbon nanoparticle loadings can reduce the metallic copper coordination number. At a copper coordination number of 4.2 we demonstrate a CO 2 -to-methane selectivity of 62%, a methane partial current density of 136 mA cm −2 , and 110 hours of stable operation.
Publisher: Springer Science and Business Media LLC
Date: 14-05-2021
DOI: 10.1038/S41467-021-23023-0
Abstract: Membrane electrode assembly (MEA) electrolyzers offer a means to scale up CO 2 -to-ethylene electroconversion using renewable electricity and close the anthropogenic carbon cycle. To date, excessive CO 2 coverage at the catalyst surface with limited active sites in MEA systems interferes with the carbon-carbon coupling reaction, diminishing ethylene production. With the aid of density functional theory calculations and spectroscopic analysis, here we report an oxide modulation strategy in which we introduce silica on Cu to create active Cu-SiO x interface sites, decreasing the formation energies of OCOH* and OCCOH*—key intermediates along the pathway to ethylene formation. We then synthesize the Cu-SiO x catalysts using one-pot coprecipitation and integrate the catalyst in a MEA electrolyzer. By tuning the CO 2 concentration, the Cu-SiO x catalyst based MEA electrolyzer shows high ethylene Faradaic efficiencies of up to 65% at high ethylene current densities of up to 215 mA cm −2 and features sustained operation over 50 h.
Publisher: American Chemical Society (ACS)
Date: 28-01-2020
DOI: 10.1021/JACS.9B12445
Abstract: The electroreduction of carbon dioxide (CO
Publisher: Springer Science and Business Media LLC
Date: 21-08-2023
Location: United States of America
No related grants have been discovered for Yi Xu.