Research Interest
1. Gas-phase cluster chemistry;
2. Nanocluster catalysis;
3. The theoretical and computational chemistry;
4. Catalytic conversion of energy-related molecules.
Representative Research
1. On the Remarkable Role of the Nitrogen Ligand in the Gas-Phase Redox Reaction of the N2O/CO Couple Catalyzed by [NbN]+ (Angew. Chem. Int. Ed. 2019, 58, 3635–3639)
The catalytic redox reactivities in the N2O/CO system mediated by niobium-containing ions, that is, [Nb]+/[NbO]+, [NbO]+/[Nb(O)2]+, and [NbN]+/[ONbN]+, have been studied in a combined experimental/computational approach. Although all the precursor ions react efficiently with N2O to generate the higher oxides, the oxidation of CO can only be achieved with [ONbN]+. The nitrogen ligand is remarkable in its bifunctional role in the course of CO oxidation.
2. Thermal Activation of CH4 and H2 as Mediated by the Ruthenium–Oxide Cluster Ions [RuOX]+ (x = 1–3): On the Influence of Oxidation States (Chem.-Eur. J. 2019, 25, 3550-3559)
The higher oxidization states of the Ru centers in the [RuO2,3]+/CH4 systems lead to deeper oxidation products, including the generations of formaldehyde and syngas. The reduction of Ru drives the overall oxidation of methane. In contrast to the high reactivity of [RuO3]+ with CH4, this oxide is inert towards H2. While favorable back-bonding orbital interactions between dihydrogen and [RuO1, 2]+ pull down the respective transition states, the inertness of [RuO3]+/H2 results from the rather small electronic interactions as well as the low polarizability of dihydrogen.
3. On the Origin of the Distinctly Different Reactivity of Ruthenium in [MO]+/CH4 Systems (M=Fe, Ru, Os) (Angew. Chem. Int. Ed. 2018, 57, 5934–5937)
In contrast to the previously studied [FeO]+/CH4 and [OsO]+/CH4 couples, which undergo oxygen/hydrogen atom transfers and dehydrogenation, respectively, the [RuO]+/CH4 system produces selectively [Ru(CH)2]+ and H2O, albeit with much lower efficiency. Various mechanistic scenarios were uncovered, and the associated electronic origins were revealed by high-level quantum-chemical calculations. The reactivity differences observed for the [MO]+/CH4 couples (M=Fe, Ru, Os) are due to the subtle interplay of the spin–orbit coupling efficiency, orbital overlap, and relativistic effects.
4. Metal-Free, Room-Temperature Oxygen-Atom Transfer in the N2O/CO Redox Couple as Catalyzed by [Si2OX].+ (x=2–5) (Angew. Chem. Int. Ed. 2017, 56, 9990–9993)
The catalytic reduction of N2O by CO by the main-group, metal-free cluster cations [Si2OX].+ (x=2–5) has been demonstrated for the first time in a combined experimental/computational study. Three sequential oxidation/reduction steps occur, and theoretical investigations reveal that oxygen-centered radicals play a role in the O-atom transfer to CO from [Si2OX].+ (x=3, 4). The overall catalytic redox process is further promoted by the strong electrostatic interaction between the cluster ions and the incoming substrates. The set of results presented may help to better understand condensed-phase, silica-based catalytic redox reactions, and may prove helpful in the design of more efficient catalysts.
5. Thermal Methane Activation by [Si2O5]+ and [Si2O5H2]+: Reactivity Enhancement by Hydrogenation (Angew. Chem. Int. Ed. 2016, 55, 13345–13348)
Thermal methane activation promoted by hydrogenation of the [Si2O5].+ cluster has been demonstrated in a combined experimental/computational study. The hydrogenation results in the re-distribution of the spin to produce an active site in form of a terminal oxo group; it is this terminal oxo group which then brings about efficient homolytic C-H bond scission. This finding of the thermal activation of methane by a polynuclear, oxygen-rich silicon oxide cluster may provide insight into the reactivity of more-complicated silica-based catalytic systems.
Contact
sunxy@qibebt.ac.cn
