Synthesis and Study of Palladium Mono- and Bimetallic (with Ag and Pt) Nanoparticles in Catalytic and Membrane Hydrogen Processes

Abstract

A controlled strategy for the electrochemical synthesis of mono- and bimetallic nanoparticles with a unique and complex morphology has been developed. The investigation of the effect of changing the surfactant concentration and current density regulating the medium pH has revealed the fundamental patterns of nanoparticle growth. The developed method has allowed to synthesis of nanoparticles with a controlled pentabranched structure for the monometallic palladium as well as for favorable combinations of metals—Pd-Ag and Pd-Pt. The obtained nanoparticles were investigated in alkaline methanol oxidation. The results demonstrated quite high catalytic activity up to 83.51 mA cm−2 and long-term stability, which are caused by the increase in electrochemically active surface area by increasing the active center’s number. This was made possible due to the creation of unusual nanoparticle morphology, namely the presence of high-energy high-index facets. The developed nanoparticles were also studied as a modifying coating for hydrogen-permeable membranes in the processes of hydrogen transport. The membranes coated with the nanoparticles demonstrated sufficiently high hydrogen flux up to 11.33 mmol s−1 m−2 and high H2/N2 selectivity up to 2254. Such results can be explained by the obvious acceleration of surface processes through the application of the developed nanoparticles. The novel synthesis strategy can potentially be extended to other metal nanoparticle systems. Thus it can be an effective way to solve relevant problems of design of controlled synthetic methods allowing the nanoparticle morphology tuning according to the required functional properties.

Electronic and Coordination Effect of PtPd Nanoflower Alloys for the Methanol Electrooxidation Reaction

“…). , Among them, the alloy strategy has received increasing research interest due to the minimization of poisoning effects and greatly enhanced MOR performance, which depends on the specific properties of the additional metal. Particularly, modifying Pt by introducing M metals (M = Ru, Pd, Au, Sn, Ni, etc.) can significantly adjust the electronic structure and d-band center of Pt, which is beneficial for the adsorption and activation of methanol.…”

Hydrogen Permeability of Composite Pd–Au/Pd–Cu Membranes and Methods for Their Preparation

“…The deposition of a modifier based on pentagonal structured, multiply twinned nanoparticles is particularly interesting and effective. Membranes modified with such a coating make it possible to increase hydrogen permeability by several times in the low-temperature operating range [ 57 , 58 ]. The novelty of the work is the study of the effect of surface modifiers of various morphologies on membrane materials in low-temperature hydrogen transportation.…”

Investigation of the Dependence of Electrocatalytic Activity of Copper and Palladium Nanoparticles on Morphology and Shape Formation

“…Metal nanoparticles with certain facets and shapes differ from bulk materials in terms of thermal, optical, electrical, and magnetic aspects due to their unique morphology and size effects. This makes them promising materials in the field of catalysis [1,2], spectroscopy [3], nanomedicine [4,5], electronics [6,7], energy conversion [8], and hydrogen energy, including high-purity hydrogen evolution (99.999% purity) [9][10][11][12], etc. The branch of synthesis of functional nanostructured coatings with a greater specific active surface area and improved catalytic, protective, and other necessary properties is of great interest [13][14][15].…”