Pd-P nanoparticles supported on P_xO_y-incorporated carbon nanotubes for enhanced methanol oxidation in an alkaline medium

Abstract

Phosphorous oxide (PO)-incorporated carbon nanotubes (PCNTs) and nitric acid treated carbon nanotubes (OCNTs) are first synthesized, then phosphorous modified palladium nanoparticles (Pd-P NPs) supported on PCNTs (Pd-P/PCNTs) and OCNTs (Pd-P/OCNTs) are synthesized and employed as electrocatalysts in a methanol oxidation reaction. Pd-P/PCNTs show enhanced electrocatalytic activity and stability in comparison to Pd-P/OCNTs. Combining surface analysis and electrochemical performance, PO incorporated into CNTs could create anchoring sites for Pd ions and P precursors, which could facilitate the synthesis of Pd-P NPs in an aqueous solution containing Pd ions and sodium hypophosphite serving as a reducing agent and a P source. The electronic modification of embedded Pd-P NPs on PO-incorporated CNTs accounts for the enhanced electrochemical performance of Pd-P/PCNTs.

NiCuCo2O4 Supported Ni–Cu Ion-Exchanged Mesoporous Zeolite Heteronano Architecture: An Efficient, Stable, and Economical Nonprecious Electrocatalyst for Methanol Oxidation

“…It is well documented that the lower the value of the Tafel slope, the higher will be the electrocatalytic activity. A lower magnitude of Tafel slope also indicates higher tolerance of the active electrocatalyst toward the poisoning species . Results obtained from the Tafel slope indicate that among the three modified electrodes, Ni 0.5 Cu 0.5 Co 2 O 4 (30%)/Ni 2 Cu 1 -MesoZ/GCE has the lowest Tafel slope (Figure ) and therefore exhibits a strong tolerance behavior toward the various intermediate species, which is the prime reason for its higher methanol electro-oxidation ability.…”

“…A lower magnitude of Tafel slope also indicates higher tolerance of the active electrocatalyst toward the poisoning species. 53 Results…”

Emerging interstitial/substitutional modification of Pd-based nanomaterials with nonmetallic elements for electrocatalytic applications

“…Among them, NaH 2 PO 2 is the most popular by acting as both a reducing agent and a phosphorous source to synthesize PdP x based on the homogeneous precipitation reduction method in aqueous solution or a phosphorization process under high temperature with a N 2 flow. 27,82,[94][95][96] During this process, breaking strong P-O bonds can be facilitated by metal particles which enhance the adsorption of H on metal and spill over from the phosphate, giving rise to the reduction of phosphate to phosphide. 97 Shao and co-workers reported that highly dispersed and ultrafine Pd-P NPs with an fcc structure supported on O-functionalized carbon nanotubes (OCNTs) could be synthesized by the reduction of Pd(II), with NaH 2 PO 2 as a reducing agent and P source in aqueous solution upon heating at 80 °C for 4 h. 95 For the nanomaterial-based catalysts, the morphology has a significant influence on the catalytic performance.…”

“…27,82,[94][95][96] During this process, breaking strong P-O bonds can be facilitated by metal particles which enhance the adsorption of H on metal and spill over from the phosphate, giving rise to the reduction of phosphate to phosphide. 97 Shao and co-workers reported that highly dispersed and ultrafine Pd-P NPs with an fcc structure supported on O-functionalized carbon nanotubes (OCNTs) could be synthesized by the reduction of Pd(II), with NaH 2 PO 2 as a reducing agent and P source in aqueous solution upon heating at 80 °C for 4 h. 95 For the nanomaterial-based catalysts, the morphology has a significant influence on the catalytic performance. In comparison with 0D isotropic NPs, 1D noble metal nanowires (NWs) and 3D nanoparticle networks (NNs) can not only facilitate the electron/mass transfer and magnify the active area accessible to the reactant molecules, but also improve the stability by decreasing the Ostwald ripening and inherent dissolution processes during the electrocatalysis.…”

Mn-doped nickeltitanate (Ni1−xMnxTiO3) as a promising support material for PdSn electrocatalysts for methanol oxidation in alkaline media

“…Before the actual performance of the experiments, een successive cycles were run to stabilize the working electrode. 40 The electrochemical performance of methanol oxidation was analyzed by the forward peak current density (I f ), and the backward current density (I b ) and the ratio of the I f and I b that is the maximum current density has been calculated from the CV curve 41 in Fig. 6.…”