Combining nanoparticles grown by ALD and MOFs for gas separation and catalysis applications

Abstract

Supported metallic nanoparticles (NPs) are essential for many important chemical processes. In order to implement precisely tuned NPs in miniaturized devices by compatible processes, novel nanoengineering routes must be explored. Atomic layer deposition (ALD), a scalable vapor phase technology typically used for the deposition of thin films, represents a promising new route for the synthesis of supported metallic NPs. Metal–organic frameworks (MOFs) are a new exciting class of crystalline porous materials that have attracted much attention in the recent years. Since the size of their pores can be precisely adjusted, these nanomaterials permit highly selective separation and catalytic processes. The combination of NPs and MOF is an emerging area opening numbers of applications, which still faces considerable challenges, and new routes need to be explored for the synthesis of these NPs/MOF nanocomposites. The aim of this paper is double: first, it aims to briefly present the ALD route and its use for the synthesis of metallic NPs. Second, the combination of ALD-grown NPs and MOFs has been explored for the synthesis of Pd NPs/MOF ZIF-8, and several selected examples were ALD-grown NPs and MOFs have been combined and applied gas separation and catalysis will be presented.

Tunable TiO2–BN–Pd nanofibers by combining electrospinning and atomic layer deposition to enhance photodegradation of acetaminophen

“…50,51 ALD enables the synthesis of nanoparticles and thin films with controllable dimensions at the subnanoscale, a unique capability. 52–57 The use of ALD in the catalysis field is getting more attention since it enables the design of nanocatalysts with control over size, composition, thickness and distribution of the material. 58 For example, Weber et al reported the synthesis of carbon paper-boron nitride-palladium electrodes using ALD, the electrochemical active surface of which remained stable even after applying an accelerated ageing program for 1000 cycles.…”

Tandem Catalytic Systems Integrating Biocatalysts and Inorganic Catalysts Using Functionalized Porous Materials

“…MOFs contain tunable pores that maintain the ability to be functionalized after synthesis, making them good supports for compartmentalizing catalysts for competing reactions. These porous materials have been used in several applications from drug delivery to gas separations and catalysis; each application typically requires a separate design and structure, both tuned by the many different options available in metal nodes and ligands. − MOF-5 was one of the first MOFs to be synthesized with a porous, crystalline structure and high porosity, alongside MOF-177. , MOF-74 and HKUST-1 have desirable porous structures and potential catalytic activity because of their open-metal sites (Figure ). − The pore size can be manipulated by ligand identity, catalytic sites can be incorporated via metal nodes, and multiple active sites can be combined into a single system.…”

On the Use of MOFs and ALD Layers as Nanomembranes for the Enhancement of Gas Sensors Selectivity

“…An increasing number of studies have focused on the size-selective sieving properties of MOFs to take up specific guest molecules in gas sensing devices. For instance, the chemically robust and thermally stable zinc-based zeolite imidazole framework (ZIF-8) has been recently used as a membrane in semiconductor metal oxides (SMOs)-based sensors for selective gas sensing [54,55,56,57,58,59,60,61]. Owing to its large cavities (11.6 Å) and small pores apertures (3.4 Å), ZIF-8 allows the selective permeation of gas molecules smaller than the pores aperture while rejecting the penetration of larger gas molecules.…”