Atomically dispersed vanadium oxides on multiwalled carbon nanotubes via atomic layer deposition: A multiparameter optimization

Abstract

The focus of the present work is to investigate the bonding characteristics of vanadium oxide species to different oxygen functional groups on multiwalled carbon nanotubes (MWCNT). Atomic layer deposition (ALD) was used to deposit atomically dispersed vanadium oxide species on MWCNT. To generate atomically dispersed vanadium, only one ALD cycle was applied for the deposition of vanadium. The MWCNT functional groups that are involved in the deposition process were identified by thermal analysis and grafting experiments. A variety of ALD process parameters were tested, and revealed that purging times between dosing of vanadium precursor and dosing of water as coreactant had a strong influence on the ratio of vanadium species that are physisorbed or chemisorbed to the MWCNT. The ALD process parameters were optimized to focus on the immobilization of the vanadium due to a chemical bond between vanadium species and MWCNT. Because of the direct correlation between catalytic stability and immobility of the vanadium species, the importance of knowledge about the influence of the ALD parameter onto the bond formation is essential. Raman spectroscopy and high resolution scanning transmission electron microscopy images were used to prove the single site structure of the vanadium oxide

Atomic Layer Deposition-Assisted Synthesis of Embedded Vanadia Catalysts

“…Alternatively, gas-phase deposition techniques such as chemical vapor deposition (CVD) or ALD can be used to graft VO x onto a supporting surface. The feasibility of producing highly dispersed VO x on different substrates by using ALD has been reported previously. − Furthermore, catalysts prepared by one of the two methods, impregnation and gas-phase deposition, have already been studied in oxidative dehydrogenation (ODH) reactions of methanol and ethanol regarding structural and catalytic properties. , …”

The Role of Supported Atomically Distributed Metal Species in Electrochemistry and How to Create Them

“…In selective hydrogenation of 1,3‐butadiene, the catalyst achieved high activity, selectivity and high durability. In recent work, our group used oxidized CNT as a substrate to load vanadium by the ALD method (Figure ) . It was confirmed that the vanadium precursor vanadium‐oxytriisopropoxide not only reacts with phenolic groups, but also forms chemical bonds with carboxylic and anhydride groups.…”

Oxidation Behavior of Glassy Carbon in Acidic Electrolyte

“…[8][9][10] In another part, carbon is often being used as catalyst support for those metal species to provide good electron transfer ability or to enhance the catalyst dispersity. [11,12] Commercial glassy carbon electrodes are often used to coat with different catalysts to study the performance of the electrocatalysts. In this case, the carbon support is considered to be totally inert to the electrolytes and the applied potentials.…”

“…In some cases, oxygen‐functionalized carbon materials were used as catalysts for oxidation evolution reaction (OER), in spite of carbon corrosion at oxidative potential [8–10] . In another part, carbon is often being used as catalyst support for those metal species to provide good electron transfer ability or to enhance the catalyst dispersity [11,12] . Commercial glassy carbon electrodes are often used to coat with different catalysts to study the performance of the electrocatalysts.…”