We study the production of terephthalic acid (TA) from biomass-derived aromatic oxygenates. Among several heterogeneous catalysts tested, a carbon-supported Ir catalyst in 4-heptanone solvent gives the best TA yield from 1,4-dihydroxymethylbenzene. A maximum 76% TA yield is achieved at 100 °C and 12 bar O₂. Based on kinetic measurements, we show that the reaction progresses in two distinct pathways. First, the alcohol groups of the substrate are converted to the aldehydes via an O-assisted dehydrogenation pathway over Ir, and then the aldehydes are oxidized to the acid in the solution via a free radical mechanism. We demonstrate that it is easier to oxidize aromatic diols than p-xylene over a heterogeneous catalyst, and thus, the biomass route to TA may be an attractive alternative to the commercial crude oil-based process.

我们研究了从生物质衍生的芳香族含氧化合物生产对苯二甲酸（TA）。在测试的几种非均相催化剂中，在4-庚酮溶剂中的碳载Ir催化剂从1,4-二羟基甲基苯获得的TA产率最高。在100°C和12 bar O _2的条件下，TA的最大收率达到76％。基于动力学测量，我们表明反应在两个不同的途径中进行。首先，底物的醇基通过Ir上的O辅助脱氢途径转化为醛，然后醛通过自由基机理氧化为溶液中的酸。我们证明，在非均相催化剂上，氧化芳香族二醇比对二甲苯更容易，因此，生物质通向TA的途径可能是商业化基于原油的工艺的有吸引力的替代方法。