Heterogeneous single-site catalysts are ideal alternatives to their homogenous counterparts. Methanol carbonylation to produce acetic acid is a typical homogeneous catalytic process. Here, we investigate the stability of a heterogeneous single-site catalyst for vapor methanol carbonylation constituted by an Ir–La binuclear complex on activated carbon (Ir₁-La₁/AC). Through the structure of the binuclear complex on the Ir₁-La₁/AC catalyst, the La promoter could protect the Ir⁺ species from reduction by H₂, favor the single-atom dispersion of Ir metal, and also increase the reaction rate of methanol carbonylation. Furthermore, the apparent activation energy of the Ir₁-La₁/AC catalyst was 12.2 kJ/mol lower than that of the Ir₁/AC catalyst. A density functional theory calculation showed that reductive elimination of acetyl iodide was the rate-determining step for the Ir₁/AC catalyst, leading to a severe carbon deposition problem, while CO migration insertion was believed to be the rate-determining step on the Ir₁-La₁/AC catalyst, which can reduce the carbon deposition to a great extent.

非均相单中心催化剂是其均相催化剂的理想替代品。甲醇羰基化生成乙酸是典型的均相催化过程。在这里，我们研究了由活性炭上的Ir-La双核络合物（Ir ₁ -La ₁ / AC）构成的用于蒸汽甲醇羰基化的非均相单中心催化剂的稳定性。通过在Ir ₁ -La ₁ / AC催化剂上双核络合物的结构，La促进剂可以保护Ir ⁺物种不被H ₂还原，有利于Ir金属的单原子分散，并提高反应速度。甲醇羰基化。此外，Ir ₁的表观活化能-La ₁ / AC催化剂比Ir ₁ / AC催化剂低12.2kJ / mol 。密度泛函理论计算表明，还原消除乙酰碘是Ir ₁ / AC催化剂的决定速率的步骤，导致严重的碳沉积问题，而CO迁移插入被认为是Ir的决定速率的步骤。₁ -La ₁ / AC催化剂，可以大大减少碳的沉积。