Atomic layer deposition of highly dispersed Pt nanoparticles on a high surface area electrode backbone for electrochemical promotion of catalysis

Abstract

A novel catalyst design for electrochemical promotion of catalysis (EPOC) is proposed for overcoming the main bottlenecks that limit EPOC commercialization, i.e., low dispersion and surface area of metal catalysts. We have increased surface area by using a porous composite electrode backbone made of (La0.8Sr0.2)0.95MnO3-δ/Ce0.9Gd0.1O1.95 (LSM/GDC). Highly dispersed Pt nanoparticles with an average diameter of 6.5 nm have been deposited on LSM/GDC by atomic layer deposition (ALD). This novel design offers, for the first time, a controllable and reproducible way for the fabrication of EPOC catalysts. The performance of the bare electrode backbone shows negligible activity for propane oxidation, while in the presence of Ptnanoparticles a high catalytic activity is obtained above 200 o C. The performance of the Pt loaded LSM/GDC catalyst was significantly improved by application of small currents (I < 500 μΑ), leading to 27-33% increase as a function of the open circuit catalytic rate, with apparent Faradaic efficiency values from 1000 to 3860 % at 300 o C. Our results point out to EPOC as valid approach to enhance the catalytic activity of nano-structured catalysts.

Catalytic and Electrochemical Properties of Ag Infiltrated Perovskite Coatings for Propene Deep Oxidation

“…Such electrochemical promotion upon positive polarization of metallic nanoparticles dispersed in an MIEC layer has been reported in the literature on Pt and Pd nanoparticles for propane or methane oxidation [22][23][24]. However, the catalytic rate of Ag/LSCF com -SP was found to slightly decrease under the application of the first positive polarization (+20 µA, Figure S6) for reaching a stable value not modified by further anodic polarizations.…”

Theoretical insight into the origin of the electrochemical promotion of ethylene oxidation on ruthenium oxide

“…The rates increase due to EPOC and supporting the catalysts on active metal oxides were similar in the case of platinum and ruthenium catalysts 11 . Furthermore, many highly dispersed electrochemically promoted systems have been established, rendering the practical application of EPOC more attractive 11,12,[21][22][23][24][13][14][15][16][17][18][19][20] . Experimentally, the origin of EPOC is mostly explained by the electrochemically induced promoters (see Figure 1), which have been substantiated by many in-situ and ex-situ techniques: x-ray photoelectron spectroscopy (XPS) 25,26 , in-situ XPS 27 , temperatureprogrammed desorption (TPD) 28,29 , scanning tunneling microscopy (STM), photoemission spectroscopy (PES) 30 , in-situ AC impedance spectroscopy 31,32 , and isotopic exchange 33 .…”

Overpotential analysis of alkaline and acidic alcohol electrolysers and optimized membrane-electrode assemblies

“…electrolysis of iso-propanol shows high anodic overpotentials at both acidic and alkaline polymeric electrolytes, suggesting that iso-propanol electrolysis is not a viable technology under the tested conditions. We assume that the high anodic overpotentials obtained with iso-propanol are mainly related to the formation of strongly adsorbed intermediates [44][45][46][47][48][49][50][51][52][53][54][55][56][57][58][59][60] .…”

“…ALD is a thin-film deposition technique which has recently attracted much attention for the fabrication of electrocatalysts. ALD offers uniform dispersion of sizecontrollable catalyst nanoparticles over the entire surface of 3D substrates [50][51][52] .…”