Bifunctional hydrodeoxygenation catalysts containing both metal and metal oxide phases are widely employed in biomass upgrading reactions. Determining the oxidation state of metals in such complex reaction media has been challenging. In this work, we developed a high-pressure trickle-bed reactor capable of conducting temperature-programed reduction of catalysts after liquid-phase reactions without exposing the catalyst bed to ambient conditions. Two case studies on metal/metal oxide catalysts employed in key biomass upgrading processes were investigated. The reduction of the RuO_x phase in Ru/RuO_x/SiO₂ occurs at temperatures as low as 115 °C via catalytic transfer hydrogenation reactions using liquid 2-propanol as a hydrogen source. Pretreatment of Ir-ReO_x/SiO₂ catalyst with H₂ in the presence of either liquid cyclohexane or liquid water reduces Re to an oxidation state of +2.6, while the residual ReO_x phase cannot be reduced in H₂ at up to 900 °C.

中文翻译：

---

ckle流床反应器液相加氢脱氧反应中金属/金属氧化物催化剂中氧化态的表征

包含金属和金属氧化物相的双功能加氢脱氧催化剂被广泛用于生物质提质反应中。在这种复杂的反应介质中确定金属的氧化态一直是一项挑战。在这项工作中，我们开发了一种高压滴流床反应器，该反应器能够在液相反应后进行程序升温还原催化剂，而无需将催化剂床暴露在环境条件下。研究了关键生物质提质过程中使用的金属/金属氧化物催化剂的两个案例研究。通过使用液态2-丙醇作为氢源的催化转移氢化反应，Ru / RuO _x / SiO _2中RuO _x相的还原在低至115℃的温度下发生。Ir-ReO的预处理在液态环己烷或液态水存在下，具有H _2的x / SiO ₂催化剂将Re还原为+2.6的氧化态，而在最高900°C的H ₂中无法还原残留的ReO _x相。