Separation and Recovery of Precious and Rare Metals Utilizing Metal Ion-Reducing Bacteria and Its Application to Fabrication of Metal Nanoparticle Catalysts

Developing sustainable energy strategies based on CO2 reduction is an increasingly important issue given the world’s continued reliance on hydrocarbon fuels and the rise in CO2 concentrations in the atmosphere. An important option is electrochemical or photoelectrochemical CO2 reduction to carbon fuels. We describe here an electrodeposition strategy for preparing highly dispersed, ultrafine metal nanoparticle catalysts on an electroactive polymeric film including nanoalloys of Cu and Pd. Compared with nanoCu catalysts, which are state-of-the-art catalysts for CO2 reduction to hydrocarbons, the bimetallic CuPd nanoalloy catalyst exhibits a greater than twofold enhancement in Faradaic efficiency for CO2 reduction to methane. The origin of the enhancement is suggested to arise from a synergistic reactivity interplay between Pd–H sites and Cu–CO sites during electrochemical CO2 reduction. The polymer substrate also appears to provide a basis for the local concentration of CO2 resulting in the enhancement of catalytic current densities by threefold. The procedure for preparation of the nanoalloy catalyst is straightforward and appears to be generally applicable to the preparation of catalytic electrodes for incorporation into electrolysis devices.

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Effect of Substitutionally Doped Graphene on the Activity of Metal Nanoparticle Catalysts for the Hydrogen Oxidation Reaction

ACS Catalysis ◽

10.1021/acscatal.8b03338 ◽

2018 ◽

Vol 9 (2) ◽

pp. 1129-1139 ◽

Cited By ~ 12

Author(s):

Stephen A. Giles ◽

Yushan Yan ◽

Dionisios G. Vlachos

Keyword(s):

Oxidation Reaction ◽

Hydrogen Oxidation ◽

Metal Nanoparticle ◽

Hydrogen Oxidation Reaction ◽

Nanoparticle Catalysts ◽

Doped Graphene

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Volcano-Type Correlation between Particle Size and Catalytic Activity on Hydrodechlorination catalyzed by AuPd Nanoalloy

10.26434/chemrxiv.12818783 ◽

2020 ◽

Author(s):

Yuta Uetake ◽

Sachi Mouri ◽

Setsiri Haesuwannakij ◽

Kazu Okumura ◽

Hidehiro Sakurai

Keyword(s):

Catalytic Activity ◽

Metal Ion ◽

Mixing Time ◽

Metal Nanoparticle ◽

Edge Structure ◽

X Ray ◽

Rate Determining Step ◽

Transmission Electron ◽

Random Alloy ◽

X Ray Absorption

<div>Although changing the size of metal nanoparticle (NP) is a reasonable way to tune and/or enhance their catalytic activity, size-selective preparation of NP possessing random-alloy morphology has been challenging because of the differences in the ionization potential of each metal ion. This study demonstrates a time-controlled aggregation–stabilization method for a size-selective preparation of random alloy NPs composed of Au and Pd, which are stabilized by poly(<i>N</i>-vinyl-2-pyrrolidone) (PVP). By adjusting the mixing time in the presence of a small amount of PVP, the aggregation was induced to produce AuPd:PVP with sizes ranging between 1.2 and 8.2 nm at approximately 1 nm intervals. Transmission electron microscopy (TEM), powder X-ray diffraction (PXRD), and extended x-ray absorption fine structure (EXAFS) analyses clearly indicated the formation of various sizes of AuPd nanoalloys with almost the same morphology, and size-dependent catalytic activity was observed when hydrodechlorination of 4-choroanisole was performed using 2-propanol as a reducing agent. AuPd:PVP with a size of 3.1 nm exhibited the highest catalytic activity. A comparison of the absorption edges on x-ray absorption near edge structure (XANES) spectra suggested that the electronic state of the Au and Pd species correlated with their catalytic activity, presumably affecting the rate-determining step.</div><div> </div>

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Soluble porous carbon cage-encapsulated highly active metal nanoparticle catalysts

Journal of Materials Chemistry A ◽

10.1039/d1ta01352a ◽

2021 ◽

Author(s):

Hangyu Liu ◽

Liyu Chen ◽

Chun-Chao Hou ◽

Yong-Sheng Wei ◽

Qiang Xu

Keyword(s):

Porous Carbon ◽

Metal Organic Framework ◽

Metal Nanoparticle ◽

Hydrogen Peroxide Decomposition ◽

Carbon Cage ◽

Nanoparticle Catalysts ◽

Highly Active ◽

Active Metal ◽

Peroxide Decomposition ◽

Metal Organic

Metal nanoparticles are encapsulated within soluble porous carbon cages by a silica-shelled metal–organic framework pyrolysis approach. The catalyst shows high catalytic activities for hydrogen peroxide decomposition and ammonia borane hydrolysis.

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