Decarboxylation of beta-keto acids in enzymatic and heterogeneous catalysis has been considered in the literature as an irreversible reaction due to a large positive entropy change. We report here experimental evidence for its reversibility in heterogeneous catalysis by solid metal oxide(s) surfaces. Ketones and carboxylic acids having ¹³C-labeled carbonyl group undergo ¹³C/¹²C exchange when heated in an autoclave in the presence of ¹²CO₂ and ZrO₂ catalyst. In the case of ketones, the carbonyl group exchange with CO₂ serves as evidence for the reversibility of all steps of the catalytic mechanism of carboxylic acids ketonic decarboxylation, i.e. enolization, condensation, dehydration and decarboxylation.

在酶催化和非均相催化中，β-酮酸的脱羧由于大的正熵变化而被认为是不可逆的反应。我们在这里报告其固体金属氧化物表面多相催化可逆性的实验证据。当在具有¹² CO ₂和ZrO ₂催化剂的高压釜中加热时，具有¹³ C-标记的羰基的酮和羧酸进行¹³ C / ¹² C交换。在酮的情况下，羰基与CO ₂交换 作为羧酸酮酮脱羧催化机理所有步骤的可逆性的证据，即烯醇化，缩合，脱水和脱羧。