On the Reactivity of Carbon Supported Pd Nanoparticles during NO Reduction: Unraveling a Metal–Support Redox Interaction

Abstract

Pd nanoparticles (NPs) were successfully obtained by the reduction of PdCl2 with L-ascorbic acid, whose morphology was revealed by HRTEM to be a worm-like system, formed by linked crystallite clusters with an average short-axis diameter of 5.42 nm. In situ UV-vis absorption measurements were used to monitor their formation, while XPS and XRD characterization confirmed the NPs' metallic state. A straightforward way to support the obtained Pd NPs on activated carbon (AC) was used to prepare a catalyst for NO decomposition reaction. The Pd/AC catalysts proved to be highly active in the temperature range of 323 to 673 K, and a redox mechanism is proposed, where the catalyst's active sites are oxidized by NO and reduced by carbon, emitting CO2 and enhancing their capacity to absorb and dissociate NO.

Design and synthesis of palladium/graphitic carbon nitride/carbon black hybrids as high-performance catalysts for formic acid and methanol electrooxidation

“…Additionally, it is found that the Pd 3d spectrum in Fig. 2(d) consists of four components, which are metallic Pt (335.8 and 341.1 eV), Pd 2þ (337.1 and 342.5 eV), Pd 4þ (338.6 and 343.9 eV) and Pd satellite peak (342.7 eV) [6,35,36]. Compared with the Pd-CB sample (335.2 eV), the Pd peak position of Pd-gCN-CB-30 (335.8 eV) shifted to higher binding energies, which is related to the enhanced attraction force between Pd atoms and g-C 3 N 4 /carbon black support [37,38].…”

Charge transfer effects on the chemical reactivity of PdxCu1−xnanoalloys

“…The component at the lowest BE (335.2 eV) corresponds to Pd-Pd in Pd 0 . 21,25,33 At a higher BE 7.2 eV, there is a 3d-electron shake-up satellite, which has been related to the zero-valent Pd. 25,34 In the bimetallic samples this zero-valent component has been labelled…”

“…Herein we demonstrate an approach to easily produce Pd x Cu 1−x nanoalloys (x = 0.7, 0.5 and 0.3) under mild chemical reduction conditions: aqueous medium, ambient temperature and pressure, using ascorbic acid and sodium citrate as reducing and stabilizing agents. The synthetic procedure used here is a modification of those previously reported 21,22 to obtain Pd, Pt and Ag NPs, and it is intended to minimize the hazards associated with the synthesis, as well as the consumption of energy and the use of costly materials. The as-synthesized Pd x Cu 1−x nanoparticles were analyzed by TEM (transmission electron microscopy) and HRTEM (high resolution TEM).…”

Enhanced Catalytic Dechlorination of 1,2-Dichlorobenzene Using Ni/Pd Bimetallic Nanoparticles Prepared by a Pulsed Laser Ablation in Liquid

“…Monometallic Pd NPs were synthesized by mixing the PdCl 2 stock solution, prepared by dissolving PdCl 2 in methanol with 0.01 M ascorbic acid (as a reductant) solution, into the Ni colloidal solution with constant stirring at room temperature. Pd/Ni bimetallic NPs were fabricated by mixing the PdCl 2 stock solution into the Ni colloidal solution prepared by PLAL without the reductant [51,52]. When the PdCl 2 stock solution was added to the Ni colloidal solution, the color of the sample changed from dark brown to black, indicating the formation of Pd NPs.…”