21 research outputs found
Energy-efficacy comparisons and multibody dynamics analyses of legged robots with different closed-loop mechanisms
An Intrinsic Case Study of Two Homeschooled Undergraduates’ Decisions to Become and Remain Music Education Majors
Vanadocene-Mediated Ionization of Water in the Aqua Species [H2OB(C6F5)3]: Structural Characterization of the Hydride and Hydroxide Complexes [Cp2V(m-H)B(C6F5)3] and [Cp2V(m-OH)B(C6F5)3]
Lanthanide-Transition Metal Carbonyl Complexes: Condensation of Solvent-Separated Ion-Pair Compounds into Extended Structures
Molecular active sites in heterogeneous Ir-La/C-catalyzed carbonylation of methanol to acetates
We report that when Ir and La halides are deposited on carbon, exposure to CO spontaneously generates a discrete molecular heterobimetallic structure, containing an Ir-La covalent bond that acts as a highly active, selective, and stable heterogeneous catalyst for the carbonylation of methanol to produce acetic acid. This catalyst exhibits a very high productivity of ???1.5 mol acetyl/mol Ir??s with >99% selectivity to acetyl (acetic acid and methyl acetate) without detectable loss in activity or selectivity for more than 1 month of continuous operation. The enhanced activity can be mechanistically rationalized by the presence of La within the ligand sphere of the discrete molecular Ir-La heterobimetallic structure, which acts as a Lewis acid to accelerate the normally rate-limiting CO insertion in Ir-catalyzed carbonylation. Similar approaches may provide opportunities for attaining molecular (single site) behavior similar to homogeneous catalysis on heterogeneous surfaces for other industrial applications.close0