Gas-phase hydrogenation of furfural to furfuryl alcohol: A promising Cu/SiO₂ catalyst derived from lamellar Cu-based hydroxy double salt

We reported a promising Cu/SiO₂ catalyst derived from hydroxy double salts (HDS) by direct H₂-reduction, which achieved a marked improvement of catalytic performance especially the stability. The preferable HDS-derived Cu/SiO₂ with a Cu-loading of 25 wt% was highly active with a turnover frequency (TOF) of 81.8 h⁻¹, over which a high FFR conversion of 97.0% with 97.2% FOL selectivity could be achievable as well as a high space time yield of FOL of 0.42 g_FOL g_cat⁻¹ h⁻¹ at 160 °C, H₂/FFR = 15, and WHSV_FFR = 0.45 h⁻¹. Moreover, this catalyst was stable for at least 120 h, being 7-fold longer than that (15 h) for the one obtained by the conventional ammonia evaporation method. Use of the Cu-based HDS imparted as-obtained catalyst to a high Cu⁺/(Cu⁺+Cu⁰) ratio with good maintenance of the Cu⁺-Cu⁰ dual-site structure on the stream, which made for the markedly enhanced catalyst activity and stability.