One-pot preparation of mesoporous KxPMo12O40 (x = 1, 2, 3, 4) materials for oxidative desulfurization: electrochemically-active surface area (ECSA) determines their activity

Abstract

A series of pure polyoxometalate salts, K_x[PMo₁₂O₄₀]³⁻ (K_xPMo, x = 1, 2, 3, 4), have been successfully prepared via a one pot hydrothermal method using F127 as a template. These obtained K_xPMo materials are mesoporous, and have high surface area (>40 m² g⁻¹) without depending on the supports. In particular, these K_xPMo materials display an increased efficiency towards oxidative desulfurization (ODS). These materials could be reused, and result in the complete desulfurization of diesel in 1 h. In addition, our experimental test shows that the high activity of K_xPMo catalysts (such as K_1.0PMo, K_2.0PMo, K_3.0PMo and K_4.0PMo) are linearly correlated with their electrochemically-active surface area (ECSA). K_4.0PMo has the largest ECSA value and exposes largest number anions ([PMo₁₂O₄₀]³⁻), resulting in the best ODS activity. This study reveals the role of ECSA in the ODS reaction, providing a new understanding for ODS in mesoporous K_xPMo materials.