Water Splitting by C₆₀‐Supported Vanadium Single Atoms

Abstract

Water splitting is an important source of hydrogen, a promising future carrier for clean and renewable energy. A detailed understanding of the mechanisms of water splitting, catalyzed by supported metal atoms or nanoparticles, is essential to improve the design of efficient catalysts. Here, we report an infrared spectroscopic study of such a water splitting process, assisted by a C60 supported vanadium atom, C60V++H2O→C60VO++H2. We probe both the entrance channel complex C60V+(H2O) and the end product C60VO+, and observe the formation of H2 as a result from resonant infrared absorption. Density functional theory calculations exploring the detailed reaction pathway reveal that a quintet‐to‐triplet spin crossing facilitates the water splitting reaction by C60‐supported V+, whereas this reaction is kinetically hindered on the isolated V+ ion by a high energy barrier. The C60 support has an important role in lowering the reaction barrier with more than 70 kJ mol−1 due to a large orbital overlap of one water hydrogen atom with one carbon atom of the C60 support. This fundamental insight in the water splitting reaction by a C60‐supported single vanadium atom showcases the importance of supports in single atom catalysts by modifying the reaction potential energy surface.

Zooming in on the initial steps of catalytic NO reduction using metal clusters

“…118,119 Possible promotor effects of the substrate on which catalyst particles are deposited could even be mimicked using for instance fullerenes, as was recently shown for C 60 V + assisted photocatalytic water splitting. 120 An intriguing direction is the use of picosecond IR pulses to initiate the reaction, and study the timeresolved dynamics of such a reaction. Such a study would complete the characterization of the reactive PES, and is now actively being pursued in our laboratory.…”

“…118,119 Possible promotor effects of the substrate on which catalyst particles are deposited could even be mimicked using for instance fullerenes, as was recently shown for C60V + assisted photocatalytic water splitting. 120…”

Metal Atoms (Li, Na, and K) Tuning the Configuration of Pyrrole for the Selective Recognition of C60

“…As shown in Figure 2, the metal atoms of hosts always coordinate with the pentagon (η 5 ) of C 60 with much larger electronic density, as same as the V + C 60 single-atom catalyst. 59,60 The shortest distances between the surface of C 60 and the fragments of pyrrole compounds are about 3.40 Å showing clear π characters, which is like the interlayer spacing of graphite, 61 indicating the van der Waals' interaction. On the other hand, the average distance (Table S1) between M and pentagon of C 60 are about 3.00 Å, possibly meaning the n−π interaction and electron transfer.…”

Infrared spectra and structures of C60Rhn+ complexes

“…Fullerenemetal complexes are ideal test benches to check these characteristics in a well-controlled environment. For example, Hou et al have recently shown that a single vanadium atom supported on C 60 can efficiently catalyze the water splitting process to produce H 2 upon infrared (IR) excitation, demonstrating the importance of carbonaceous supports in single atom catalysts [26,27]. IR spectroscopy is a powerful tool to determine structural characteristics of clusters and nanoparticles.…”

“…Therefore, the messenger tagging technique was utilized, employing D 2 as tagging molecule. This technique has been well established in the past decades to obtain the vibrational spectra of molecular species via photodissociation [26,31,32]. D 2 -tagged C 60 Rh n + complexes are synthesized by seeding about 0.5% of D 2 into the He carrier gas.…”