Unravelling the Role of Interfacial Sites and Hydrogen Coverage on Inverse Pt–WO <i> _x </i> Catalyst for Selective 1,4-Butanediol Formation during Erythritol Hydrodeoxygenation

Biomass-derived erythritol is a sustainable source for producing the terminal diol, 1,4-butanediol (1,4-BDO). The limited understanding of catalyst structure–property relationships that enable selective OH removal makes this reaction challenging. In this study, Density Functional Theory (DFT) simulations are used to map the complete energy landscape for alcohol formation during the HDO of erythritol on a model inverse Pt–WOx catalyst. The simulations reveal that the preferred reaction pathway proceeds via butanetriol intermediates rather than direct successive hydroxyl elimination. Unlike in the case of glycerol HDO, C–O cleavage is not always the rate-limiting step during erythritol HDO, and the hydrogenation of dehydrated intermediates, particularly for 1,4-BDO formation, can exhibit high activation barriers, highlighting the need for multifunctional catalysts. 1,4-BDO (derived from 1,2,4-butanetriol) and 1,3-BDO are predicted to be the dominant diol products during erythritol HDO, consistent with experimental observations. Similar to glycerol, trimeric WOx nuclearity is identified as favorable for erythritol-selective HDO by facilitating hydrogenation. Although increased hydrogen coverage weakens Brønsted acid strength and raises the C–O cleavage barrier, sufficient hydrogen pressure lowers hydrogenation and H spillover barriers, enabling efficient in situ regeneration of Brønsted acid sites and promoting terminal diol formation. Accordingly, catalyst designs employing an inverse Pt–WOx configuration with maximized interfacial contact, high Pt exposure, and operation at elevated H2 pressure are predicted to enhance 1,4-BDO selectivity.