One-stone, two birds: alloying effect and surface defects induced by Pt on Cu2-xSe nanowires to boost C-C bond cleavage for electrocatalytic ethanol oxidation

Numerous reports in scientific literature claim the increased activity of Rh-containing systems towards C-C bond scission in electrocatalytic oxidation of ethanol at ambient temperatures. Due to the claimed C-C bond breaking ability, Rh-containing systems are intensively investigated and widely recognized as the most promising candidates as anode materials for ethanol-feed low temperature fuel cells. This study aims at verifying the claim of beneficial role of Rh towards C-C bond scission during low temperature ethanol electrooxidation on Pt-Rh nanoparticles. We determined that the surface-normalized amounts of CO2 produced during ethanol oxidation are comparable on Pt, Rh and Pt-Rh nanoalloys, and smaller than CO2 amounts obtained on exactly the same electrode from oxidation of monolayer of adsorbed CO. The whole amount of CO2 detected during ethanol oxidation, regardless of Rh presence, or lack of thereof, seems to come exclusively from oxidation of submonolayer of COads produced during dissociative adsorption of ethanol at low electrode potential, and its subsequent oxidation at sufficiently high electrode potential. Our work suggest that Rh-containing alloys are not more active towards C-C bond scission than pure Pt, and on both metals the mechanism of oxidation of ethanol to CO2 proceeds via the submonolayer of COads, which limits the quantity of CO2 produced from ethanol at room temperature to negligible amount. The higher activity of Rh-containing materials towards C-C bond scission claimed in literature was determined to be due to overinterpretation of selectivity data. To characterized the samples we used techniques like XPS, TEM, and cyclic voltammetry. For drove a conclusions we compere amount of CO2 detected in DEMS during ethanol oxidation reaction and so called CO stripping experiment.

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Mechanism of C–C and C–H bond cleavage in ethanol oxidation reaction on Cu2O(111): a DFT-D and DFT+U study

Physical Chemistry Chemical Physics ◽

10.1039/c7cp04630h ◽

2017 ◽

Vol 19 (38) ◽

pp. 26210-26220 ◽

Cited By ~ 11

Author(s):

Han Xu ◽

Bei Miao ◽

Minhua Zhang ◽

Yifei Chen ◽

Lichang Wang

Keyword(s):

Oxidation Reaction ◽

Ethanol Oxidation ◽

Bond Cleavage ◽

Ethanol Oxidation Reaction ◽

Specific Effects

The C–C and C–H cleavage of hydrocarbons in EOR on Cu2O(111) and the specific effects of +U were investigated by DFT+U.

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On the Lack of Beneficial Role of Rh Towards C-C Bond Cleavage During Low Temperature Ethanol Electrooxidation on Pt-Rh Nanoalloys

10.26434/chemrxiv.6281264 ◽

2018 ◽

Author(s):

Justyna Piwowar ◽

Adam Lewera

Keyword(s):

Low Temperature ◽

Electrode Potential ◽

Ethanol Oxidation ◽

Bond Cleavage ◽

Ethanol Electrooxidation ◽

Co Stripping ◽

Beneficial Role ◽

Bond Scission ◽

Oxidation Of Ethanol

Numerous reports in scientific literature claim the increased activity of Rh-containing systems towards C-C bond scission in electrocatalytic oxidation of ethanol at ambient temperatures. Due to the claimed C-C bond breaking ability, Rh-containing systems are intensively investigated and widely recognized as the most promising candidates as anode materials for ethanol-feed low temperature fuel cells. This study aims at verifying the claim of beneficial role of Rh towards C-C bond scission during low temperature ethanol electrooxidation on Pt-Rh nanoparticles. We determined that the surface-normalized amounts of CO2 produced during ethanol oxidation are comparable on Pt, Rh and Pt-Rh nanoalloys, and smaller than CO2 amounts obtained on exactly the same electrode from oxidation of monolayer of adsorbed CO. The whole amount of CO2 detected during ethanol oxidation, regardless of Rh presence, or lack of thereof, seems to come exclusively from oxidation of submonolayer of COads produced during dissociative adsorption of ethanol at low electrode potential, and its subsequent oxidation at sufficiently high electrode potential. Our work suggest that Rh-containing alloys are not more active towards C-C bond scission than pure Pt, and on both metals the mechanism of oxidation of ethanol to CO2 proceeds via the submonolayer of COads, which limits the quantity of CO2 produced from ethanol at room temperature to negligible amount. The higher activity of Rh-containing materials towards C-C bond scission claimed in literature was determined to be due to overinterpretation of selectivity data. To characterized the samples we used techniques like XPS, TEM, and cyclic voltammetry. For drove a conclusions we compere amount of CO2 detected in DEMS during ethanol oxidation reaction and so called CO stripping experiment.

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Ultrathin and Wavy PdB Alloy Nanowires with Controlled Surface Defects for Enhanced Ethanol Oxidation Electrocatalysis

ACS Applied Materials & Interfaces ◽

10.1021/acsami.1c02039 ◽

2021 ◽

Author(s):

Yaru Wang ◽

Hao Lv ◽

Lizhi Sun ◽

Xuwen Guo ◽

Dongdong Xu ◽

...

Keyword(s):

Ethanol Oxidation ◽

Surface Defects ◽

Alloy Nanowires

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Defects in Crystals

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100100962 ◽

1968 ◽

Vol 26 ◽

pp. 244-245

Author(s):

Kenneth R. Lawless

Keyword(s):

Electron Microscope ◽

Point Defects ◽

Surface Defects ◽

Chemical Properties ◽

Material Point ◽

Crystal Defects ◽

Defects In Crystals ◽

Irradiation Effects ◽

Normal Lattice ◽

Line Defects

One of the most important applications of the electron microscope in recent years has been to the observation of defects in crystals. Replica techniques have been widely utilized for many years for the observation of surface defects, but more recently the most striking use of the electron microscope has been for the direct observation of internal defects in crystals, utilizing the transmission of electrons through thin samples.Defects in crystals may be classified basically as point defects, line defects, and planar defects, all of which play an important role in determining the physical or chemical properties of a material. Point defects are of two types, either vacancies where individual atoms are missing from lattice sites, or interstitials where an atom is situated in between normal lattice sites. The so-called point defects most commonly observed are actually aggregates of either vacancies or interstitials. Details of crystal defects of this type are considered in the special session on “Irradiation Effects in Materials” and will not be considered in detail in this session.

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Characterization of homoepitaxial diamond films by Electron microscopy

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100088713 ◽

1991 ◽

Vol 49 ◽

pp. 880-881

Author(s):

D.P. Malta ◽

S.A. Willard ◽

R.A. Rudder ◽

G.C. Hudson ◽

J.B. Posthill ◽

...

Keyword(s):

Electron Microscopy ◽

Surface Defects ◽

Substrate Surface ◽

Diamond Films ◽

Chemical Vapor ◽

Polycrystalline Diamond ◽

Large Degree ◽

Rf Plasma ◽

Semiconducting Diamond

Semiconducting diamond films have the potential for use as a material in which to build active electronic devices capable of operating at high temperatures or in high radiation environments. A major goal of current device-related diamond research is to achieve a high quality epitaxial film on an inexpensive, readily available, non-native substrate. One step in the process of achieving this goal is understanding the nucleation and growth processes of diamond films on diamond substrates. Electron microscopy has already proven invaluable for assessing polycrystalline diamond films grown on nonnative surfaces.The quality of the grown diamond film depends on several factors, one of which is the quality of the diamond substrate. Substrates commercially available today have often been found to have scratched surfaces resulting from the polishing process (Fig. 1a). Electron beam-induced current (EBIC) imaging shows that electrically active sub-surface defects can be present to a large degree (Fig. 1c). Growth of homoepitaxial diamond films by rf plasma-enhanced chemical vapor deposition (PECVD) has been found to planarize the scratched substrate surface (Fig. 1b).

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