Elucidating the structure-dependent selectivity of CuZn towards methane and ethanol in CO electroreduction using tailored Cu/ZnO precatalysts.

Understanding the catalyst compositional and structural features that control selectivity is of uttermost importance to target desired products in chemical reactions. In this joint experimental-computational work, we leverage tailored Cu/ZnO precatalysts as a material platform to identify the intrinsic features of methane-producing and ethanol-producing CuZn catalysts in the electrochemical CO reduction reaction (CORR). Specifically, we find that Cu@ZnO nanocrystals, where a central Cu domain is decorated with ZnO domains, and ZnO@Cu nanocrystals, where a central ZnO domain is decorated with Cu domains, evolve into Cu@CuZn core@shell catalysts that are selective for methane (∼52%) and ethanol (∼39%), respectively.

Molecular tunability of surface-functionalized metal nanocrystals for selective electrochemical CO reduction.

Organic ligands are used in homogeneous catalysis to tune the metal center reactivity; in contrast, clean surfaces are usually preferred in heterogeneous catalysis. Herein, we demonstrate the potential of a molecular chemistry approach to develop efficient and selective heterogeneous catalysts in the electrochemical CO reduction reaction (CORR). We have tailor-made imidazolium ligands to promote the CORR at the surface of hybrid organic/inorganic electrode materials.

Nanocrystal/Metal-Organic Framework Hybrids as Electrocatalytic Platforms for CO Conversion.

The tunable chemistry linked to the organic/inorganic components in colloidal nanocrystals (NCs) and metal-organic frameworks (MOFs) offers a rich playground to advance the fundamental understanding of materials design for various applications. Herein, we combine these two classes of materials by synthesizing NC/MOF hybrids comprising Ag NCs that are in intimate contact with Al-PMOF ([Al (OH) (TCPP)]) (tetrakis(4-carboxyphenyl)porphyrin (TCPP)), to form Ag@Al-PMOF. In our hybrids, the NCs are embedded in the MOF while still preserving electrical contact with a conductive substrate.

Electron Density and Dielectric Properties of Highly Porous MOFs: Binding and Mobility of Guest Molecules in Cu(BTC) and Zn(BTC).

Two isostructural highly porous metal-organic frameworks, the well-known {Cu(BTC)} (BTC = 1,3,5-benzenetricarboxylate), often appointed with the name HKUST-1, and {Zn(BTC)} , have been investigated as models for the buildup of dielectric properties, differentiating the role of chemi- and physisorbed guest molecules and that of specific intraframework and framework-guest linkages. For this purpose, electron charge density analysis, impedance spectroscopy, density functional theory simulations, and atomic partitioning of the polarizabilities have been exploited. These analyses at different degrees of pores filling enabled one to observe structural and electronic changes induced by guest molecules, especially when chemisorbed.