In this work we address the challenge of furthering our understanding of the driving forces responsible for the metal-metal interactions in industrially relevant bimetallic nanocatalysts, by taking a comparative approach to the atomic scale characterization of two core-shell nanorod systems (AuPd and AuRh). Using aberration-corrected scanning transmission electron microscopy, we show the existence of a randomly mixed alloy layer some 4-5 atomic layers thick between completely bulk immiscible Au and Rh, which facilitates fully epitaxial overgrowth for the first few atomic layers. In marked contrast in AuPd nanorods, we find atomically sharp segregation resulting in a quasi-epitaxial, strained interface between bulk miscible metals. By comparing the two systems, including molecular dynamics simulations, we are able to gain insights into the factors that may have influenced their structure and chemical ordering, which cannot be explained by the key structural and energetic parameters of either system in isolation, thus demonstrating the advantage of taking a comparative approach to the characterization of complex binary systems. This work highlights the importance of achieving a fundamental understanding of reaction kinetics in realizing the atomically controlled synthesis of bimetallic nanocatalysts.
We present a comparative study of the activity and selectivity of Rh/C nanoparticles and Sn‐modified Rh/C nanoparticles towards electrocatalytic nitrate reduction in sulfuric acid. Electrochemical techniques, combined with more direct analytical techniques such as mass spectrometry and ion chromatography, were applied to analyse the products obtained during the reaction. Online electrochemical mass spectrometry was employed to detect volatile products, such as nitric oxide (NO), nitrous oxide (N2O) and dinitrogen (N2). The combination of online sample collection to the electrochemical cell and offline ion chromatography allows the quantitative analysis of non‐volatile products, such as ammonium (${{\rm{NH}}_{\rm{4}}^ + }$) and hydroxylamine (NH3OH+). Non‐volatile products can be detected during nitrate reduction at Rh/C electrodes. The catalytic activity of Rh/C electrodes can be enhanced by Sn modification. N2O is the dominant volatile product at SnRh/C electrodes. ${{\rm{NH}}_{\rm{4}}^ + }$ is the main ionic product at the Rh/C electrodes, whereas modification by Sn also leads to the formation of NH3OH+.
This study focuses on the deposition and growth mode
of rhodium
(Rh) on gold (Au) seed nanorods (NRs). Using a combination of scanning
transmission electron microscopy imaging, energy-dispersive X-ray
spectroscopy, and UV–visible absorption spectroscopy, we show
that
Rh deposition results in an uneven overlayer morphology on the Au
NR seeds, with a tendency for Rh deposition to occur preferentially
on the Au NR ends. The results suggest that complex and kinetically
driven metal–metal interactions take place in this system.
A highly sensitive electrochemical sensor for detection of nitrite based on nickel, poly(diallyldimethylammonium chloride) (PDDA), reduced graphene oxide (rGO) and a disposable screen-printed carbon electrode (SPCE).
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.