This work revealed 5-hydroxymethylfurfural (HMF) oxidation towards 5-hydroxymethyl-2-furancarboxylic acid (HMFCA) employed Ag₂O supported on calcium carbonate as heterogeneous catalyst in conventional batch protocols and microwave-assisted batch conditions. Different reaction regimes were investigated, such as catalyst loading, reaction temperature, solvent types and oxidizing agent concentrations. 89 % HMF conversion, 85 % HMFCA yield as well as 95 % HMFCA selectivity achieved under optimum condition (125 mg 20 wt% Ag₂O-CaCO₃, 2 wt% aq. H₂O₂ with 0.1 mL min⁻¹ flow rate in 50 min, oil bath 100 ºC). Microwave irradiation (30 W) afforded higher HMF conversion (95 %) as well as HMFCA yield (93 %) with HMFCA selectivity (97 %) under identical condition. Catalyst recycling showed deactivation (64 % HMF conversion and 50 % HMFCA yield in fourth time). Post-characterization was investigated to analyze catalyst deactivation. For instance, EDS and SEM mapping micrographs showed organic moieties deposited on the surface of catalyst. XRD exhibited no CaCO₃ crystallographic modification happened after reaction, however, partial reduction of silver (I) to metallic silver (0) happened.

这项工作揭示了在常规批处理方案和微波辅助的批处理条件下，采用负载在碳酸钙上的Ag ₂ O作为多相催化剂，将5-羟甲基糠醛（HMF）氧化为5-羟甲基-2-呋喃甲酸（HMFCA）。研究了不同的反应方式，例如催化剂负载量，反应温度，溶剂类型和氧化剂浓度。在最佳条件下（125 mg 20 wt％Ag ₂ O-CaCO _3，2 wt％H ₂ O ₂水溶液和0.1 mL min ^-1的条件下，实现89％HMF转化，85％HMFCA产率以及95％HMFCA选择性50分钟内的流速，油浴100ºC）。微波辐射（30 W）在相同条件下提供了更高的HMF转化率（95％）和HMFCA收率（93％），以及HMFCA选择性（97％）。催化剂回收显示出失活（第四次HMF转化率为64％，HMFCA产率为50％）。研究了后表征以分析催化剂失活。例如，EDS和SEM作图显微照片显示有机部分沉积在催化剂表面上。XRD反应后未发生CaCO ₃晶体学改性，但发生了部分还原银（I）为金属银（0）的现象。