Controlled Synthesis of Au-Island-Covered Pd Nanotubes with Abundant Heterojunction Interfaces for Enhanced Electrooxidation of Alcohol

Abstract

Here, we, for the first time, synthesized Pd nanotubes covered by high-density Au-islands, in which abundant exposed Pd−Au heterojunction interfaces are present and the content of element Au can be easily controlled. The optimized nanostructures show remarkably enhanced activity for catalyzing different alcohols in alkaline media than commercial Pd/C. The mass activity is 9.66, 1.83, and 4.60 A mg metal −1 toward the electrooxidation of ethanol, glycerol, and ethylene glycol in alkaline media, which is about 6, 4, and 7 times that of Pd/C, respectively. Additionally, a model was proposed to explain the relationship between the structure and the catalytic activity.

Mesoporous Decoration of Freestanding Palladium Nanotube Arrays Boosts the Electrocatalysis Capabilities toward Formic Acid and Formate Oxidation

“…An open tube with a large diameter is highly beneficial for ion accessibility and diffusion. Various wet chemical methods have been attempted for palladium nanotube synthesis . Nevertheless, most of these nanotube products were collected as piled‐up powders.…”

Research and innovation in the electrocatalyst development toward glycerol oxidation reaction

“…Xu et al 40 making a metal content ratio of 1:1, and comparing to other groups; the catalyst exhibited S C H E M E 3 Linear sweep curves of Pt (left) and Pd electrode in alkaline media 31 [Colour figure can be viewed at wileyonlinelibrary.com] unique one-dimension nanowires (1D NWs) structure due to the optimum ratio of dual capping agents, polyvidone (PVP), and C 19 H 42 BrN (CTAB). Pd-Au NWs were able to produce high mass activities for a short time, but Pt-Au NWs could retain higher mass activities for a longterm period due to better durability.Lam et al, 41 Ottoni et al, 42 Cai et al, 43 Rezaei et al, 44 Dong et al, 45 and Yahya et al 46,47 researched various molar ratios for Pd/Au catalyst. Lam et al 41 reported Pd-Au bi-functional mechanism caused oxidation removal of residual intermediate poisons on active Pd surface to enable GOR to restart.…”

“…34 They also found that the Pd/Au equilibrium composition is the most active and can break all the glycerol C C bonds in a single process, leading to carboxylic acid production pathways. Cai et al 43 synthesized through Te nanowires template, where the Pd was in the form of nanotubes 48 covered by controllable precursor, Au (Scheme 4). The structure provided Pd-Au heterogenous junctions formation and enabled the catalyst to selfsupport itself for better catalytic activity than standalone catalysts Pd/C and Pd NTs.…”

“…The mesoporous structure of the catalyst exhibited good morphology stability and durability due to unnoticeable deactivation after many cycles. Oxyphilic metal, Au with bifunctional Pd-Au mechanism at equilibrium molar S C H E M E 4 TEM, HRTEM, and HAADF-STEM-EDX images of Pd-Au NTs 43 [Colour figure can be viewed at wileyonlinelibrary.com] ratio, was able to produce the lowest onset potential, the highest power density, and the highest CO tolerance compared to monometallic and other molar ratios.Chen et al, 49 Maumau et al, 50 and Mello et al 51 synthesized Pd-Au at a fixed molar ratio. Chen et al 49 used L-hydroxyproline in their one-step wet-chemical method for the synthesis as the green stabilizer and structuredirecting agent to reduce the particles' uneven size and common Au aggregation problem.…”

One Dimensional AuAg Nanostructures as Anodic Catalysts in the Ethylene Glycol Oxidation

“…Furthermore, the use of 1D Pt and Pd nanomaterials, alloyed or decorated with Au, has shown significant catalytic activity owing to their synergistic effects and large surface areas [18,[25][26][27][28][29][30][31]. To this end, ultrathin nanowires (NWs) have become widely used in fuel cells, offering remarkable catalytic performances [32][33][34][35][36][37].…”