Wire-like Pt on mesoporous Ti0.7W0.3O2 Nanomaterial with Compelling Electro-Activity for Effective Alcohol Electro-Oxidation

Abstract

Finding out robust active and sustainable catalyst towards alcohol electro-oxidation reaction is major challenges for large-scale commercialization of direct alcohol fuel cells. Herein, a robust Pt nanowires (NWs)/Ti0.7W0.3O2 electrocatalyst, as the coherency of using non-carbon catalyst support and controlling the morphology and structure of the Pt nanocatalyst, was fabricated via an effortless chemical reduction reaction approach at room temperature without using surfactant/stabilizers or template to assemble an anodic electrocatalyst towards methanol electro-oxidation reaction (MOR) and ethanol electro-oxidation reaction (EOR). These observational results demonstrated that the Pt NWs/Ti0.7W0.3O2 electrocatalyst is an intriguing anodic electrocatalyst, which can alter the state-of-the-art Pt NPs/C catalyst. Compared with the conventional Pt NPs/C electrocatalyst, the Pt NWs/Ti0.7W0.3O2 electrocatalyst exhibited the lower onset potential (~0.1 V for MOR and ~0.2 for EOR), higher mass activity (~355.29 mA/mgPt for MOR and ~325.01 mA/mgPt for EOR) and much greater durability. The outperformance of the Pt NWs/Ti0.7W0.3O2 electrocatalyst is ascribable to the merits of the anisotropic one-dimensional Pt nanostructure and the mesoporous Ti0.7W0.3O2 support along with the synergistic effects between the Ti0.7W0.3O2 support and the Pt nanocatalyst. Furthermore, this approach may provide a promising catalytic platform for fuel cell technology and a variety of applications.

Pt Nanowires on Monolayered Graphene Oxide for Electrocatalytic Oxidation of Methanol

“…The width was about 4 nm, and the measured lattice fringe spacing was about 0.228 nm, corresponding to the (111) crystal plane of the face-centered cubic crystal structure of Pt, which indicated that Pt was mainly growing along the (111) crystal plane . The growth mechanism of Pt nanowires on GO was similar to that reported by other groups. ,,, Briefly, chloroplatinic acid was first reduced with formic acid to form platinum nuclei. The platinum nuclei were then deposited onto the monolayered GO due to the abundant oxygenated groups of GO.…”

“…In most reports on the synthesis of platinum-based nanomaterials, surfactants were usually added to control the morphology of platinum . However, surfactants would tend to adsorb on the electrocatalytically active sites of platinum, which would result in the reduction of the electrocatalytic activity of platinum . In order to avoid this problem, surfactant-free methods have been developed. , …”

“…The forward peak current ( I f ) indicated the catalytical activity of the catalyst on the oxidation of methanol. The significant higher mass activity of PtNW-GO was speculated to be related to the nanowire morphology of Pt, the conductive monolayer rGO, and the intertwined structure of Pt nanowires and GO. The reverse peak current ( I b ) was the oxidation of carbonaceous substances such as CO ads produced by the incomplete oxidation of methanol, so the I f / I b ratio represented the antipoisoning ability of the catalyst .…”

“…26 However, surfactants would tend to adsorb on the electrocatalytically active sites of platinum, 27 which would result in the reduction of the electrocatalytic activity of platinum. 28 In order to avoid this problem, surfactant-free methods have been developed. 29,30 In the present study, PtNW-GO were synthesized based on Sun's surfactant-free method.…”

“…32 The growth mechanism of Pt nanowires on GO was similar to that reported by other groups. 26,28,33,34 Briefly, chloroplatinic acid was first reduced with formic acid to form platinum nuclei. The platinum nuclei were then deposited onto the monolayered GO due to the abundant oxygenated groups of GO.…”