Thin-sheet microfibrous-structured nanoporous gold/Al fiber catalysts for oxidative coupling of methanol to methyl formate
Thin-sheet microfibrous-structured nanoporous gold/Al fiber catalysts for oxidative coupling of methanol to methyl formate
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DOI：
10.1016/j.jcat.2014.06.004
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发表时间：
2014-08
影响因子：
7.3
通讯作者：
Qiaofei Zhang;Yakun Li;Li Zhang;Li Chen;Ye Liu;Yong Lu
中科院分区：
文献类型：
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作者：
Qiaofei Zhang;Yakun Li;Li Zhang;Li Chen;Ye Liu;Yong Lu
活性、选择性和稳定的铝纤维负载的纳米孔金 (NPG) 催化剂具有增强的传热性能，已被开发用于甲醇与甲酸甲酯的氧化偶联。 NPG/Al 纤维催化剂是通过使用 50 μm Al 纤维将 AuAg 合金电镀沉积在薄片微纤维结构上，然后使用 HNO3 水溶液浸出 Ag 来脱合金而获得的。在 100 °C 时，NPG-7/Al 纤维（金负载量：7 wt%）催化剂能够在 5000 mL gcat.−1h−1 下实现 ∼100% 甲酸甲酯选择性，并且 10 vol% 甲醇进料的甲醇转化率约为 25%。金负载量可减少至 1 wt%，反应性可接受（160 °C 时转化率为 35%，选择性为 85%）。该催化剂在没有 NPG 烧结的情况下可稳定至少 300 小时。由于非选择性表面 O 物种数量的减少，降低 NPG 催化剂的 Ag 残留含量对于提高甲醇选择性至关重要。
Active, selective, and stable nanoporous gold (NPG) catalysts supported on Al fiber, with enhanced heat transfer, have been developed for the oxidative coupling of methanol to methyl formate. The NPG/Al fiber catalysts are obtainable by galvanically depositing AuAg alloy on a thin-sheet microfibrous structure using 50-μm Al fiber and subsequently dealloying by leaching Ag using HNO3aqueous solution. At 100 °C, NPG-7/Al fiber (Au loading: 7 wt%) catalyst is capable of achieving ∼100% methyl formate selectivity with ∼25% methanol conversion of a 10 vol% methanol feed at 5000 mL gcat.−1h−1. Gold loading can be reduced to 1 wt% with acceptable reactivity (35% conversion with 85% selectivity at 160 °C). The catalyst is stable for at least 300 h without NPG sintering. Lowering the Ag residual content of the NPG catalysts is essential for higher selectivity of methanol, by nature, due to the reduction in the amount of unselective surface O species.