Ultra-fast phosphating synthesis of metastable crystalline phase-controllable ultra-small MP /CNT (M = Pd, Pt, Ru) for polyalcohol electrooxidation

A series of MP X /CNT with ultra-small metastable crystalline phase-controlled are rapidly synthesized in a household microwave oven by an ultra-fast synthesis method. By altering the phosphorus source to synthesize different metastable crystalline phase Pd phosphides. A general approach is reported for ultra-fast phosphating synthesis of a series of ultra-small (<5 nm) noble metal phosphides (MP X /CNT, M = Pd, Pt, Ru) which are successfully produced in just 75 s for the first time. The catalytic performance of the catalysts can be optimized by controlling the nanomaterials as the metastable crystalline phases. By altering the phosphorus source under the same conditions, the hexagonal structured Pd 7 P 3 (NaH 2 PO 2 ·H 2 O as P source) and monoclinic structured Pd 6 P (Na 4 P 2 O 7 as P source) can be prepared successfully. Both of them exhibit excellent polyol oxidation performance in alkaline media. Monoclinic Pd 6 P/CNT and hexagonal Pd 7 P 3 /CNT have large ECSA which are confirmed as 82.1 m 2 g −1 and 86.2 m 2 g −1 , respectively. Hexagonal Pd 7 P 3 /CNT has the highest mass activity of 6.14 A mg Pd −1 (3.21 A mg Pd −1 for Pd 6 P/CNT) for GOR, which far exceeded Pt/C (2.81 A mg Pt −1 ). Meanwhile, the mass activity of monoclinic Pt 5 P 2 /CNT for EGOR achieved 12.4 A mg Pt −1 , which far exceeded Pt/C (6.8 A mg Pt −1 ). The stability test proved that the activity decay of these catalysts was negligible after the 12-hour durability test. Meanwhile, they have excellent CO anti-poisoning abilities.