Lacunary Keggin-Type Phosphomolybdate Functionalized with Ru(acac)₃ Complex for Electrocatalytic H₂ Production in Aqueous Media

Abstract

The design and manufacture of efficient and durable systems for electrocatalytic hydrogen evolution reaction (HER) is an important challenge for achieving clean and sustainable energy resources. Here, we report the synthesis and characterization of a lacunary polyoxometalate-based electrocatalyst, i.e., PMo 11 −Ru(acac) 3 through the modification of Na 7 PMo 11 O 39 (PMo 11 ) with aminopropyltrimethoxysilane and the next reaction with Ru(acac) 3 for efficient hydrogen evolution in acidic media. The results of elemental analysis as well as Fourier transform infrared and X-ray photoelectron spectroscopies approved the successful functionalization of lacunary PMo 11 with the Ru complex. The prepared electrocatalyst showed high HER activity and stability with a low overpotential of 91 mV at a current density of 10 mA cm −2 , which introduces it as an efficient electrocatalyst for HER in aqueous solution. Further investigations demonstrated that PMo 11 −Ru(acac) 3 has appropriate stability, retaining its activity after 2000 cycles. The vicinity of PMo 11 and the Ru complex has been suggested to allow possible synergism between them, leading to improved functional behavior and promoting the HER. Preparation of a new electrocatalyst is reported for application in the electrocatalytic HER. The electrocatalyst was based on the interaction of a lacunary phosphomolybdate anion and Ru(acac) 3 complex. The electrocatalyst revealed a high performance in hydrogen evolution for a prolonged time span.