When Inert Becomes Active: A Fascinating Route for Catalyst Design

Abstract

Abstract:In this personal account, we review the work of our group in the area of energy and environment related nanocatalysis in the past seven years. We focus on understanding the fundamental mechanisms, which control properties of atomic clusters and nanoparticles -a form of matter that is intermediate between atoms and their bulk counterpart. The emphasis is made on the theoretical design of effective catalysts based on cheap and abundant elements. The main idea that stands behind of our work is that even catalytically inactive or completely inert materials can be functionalized at nanoscale via the size, structure, morphology and support effects. Such approach opens principally new ways to design catalytically active systems based on materials never before been considered as catalysts. In particular we demonstrate that the hexagonal boron nitride (h-BN), which was traditionally considered as an inert material, can be functionalized and become active for a number of catalytic reactions involving oxygen activation, oxidation by molecular oxygen, and oxygen reduction reaction (ORR).

Oxygen Reduction Reaction Catalyzed by Small Gold Cluster on h-BN/Au(111) Support

“…Therefore until recently such material has never been considered as a possible candidate for electrocatalyst. However in our previous works we have demonstrated theoretically that h-BN is not as inert as it was previously believed and can strongly affect the catalytic properties of the supported metal particles [34][35][36][37][38].…”

“…It is important to note that adsorption energies of intermediates of catalytic reactions can be strongly affected by the density of electronic states (DOS) near the Fermi level. Therefore, a metal substrate or defects in h-BN can promote or affect catalytic reactions on the h-BN surface [38]. This theoretical suggestion has been proved experimentally where it has been demonstrated that Au electrodes modified with boron nitride nanosheet (BNNS) in the acid media indeed can act as effective electrocatalysts not only for ORR [47,48], but also for the hydrogen evolution reaction (HER) [49].…”

“…Nevertheless excess of the negative or positive charge on Au 8 can promote its activity towards oxygen activation [82,83]. Interaction with the support can induce charge transfer between the cluster and the surface which makes supported cluster more reactive in comparison with its free counterpart [38].…”

“…As we have already mentioned interaction between h-BN and transitionmetal occurs due to the metal-d BN-π hybridization at the h-BN/metal interface. Adding gold particle on the BN/Au(111) surface would result in increase of the density of electronic states (DOS) near the Fermi level promoting oxygen adsorption [35,38]. The Bader charge analysis shows that Au 8 on h-BN/Au(111) possesses small positive charge of 0.5e, where e is an elementary charge.…”

Enhanced and stabilized hydrogen production from methanol by ultrasmall Ni nanoclusters immobilized on defect-rich h-BN nanosheets

“…By virtue of an exceptional chemical and thermal stability, large surface area, high thermal conductivity, and strong surface adsorbing capability, two-dimensional (2D) hexagonal BN nanosheets (h-BN or BN in this paper), a structural analog of graphene, are one of the most attractive transition metal catalysts supports (28)(29)(30). The pristine BN surface is an inert support for metal nanoclusters, which would lead to catalyst deactivation by sintered metal species (31,32). Thanks to the chemical modification/doping or defect engineering, BN owns greater possibilities in changing physical and chemical characteristics for catalysis development.…”