Size-controlled tin oxide clusters, Sn n O x (n ¼ 12–60), were prepared using
accumulation of SnCl 2 to a DPA-TPM dendrimer, loaded into mesoporous silica,
followed by chemical reduction and calcination under air to remove the dendritic
template. The Sn n O x clusters are catalytically active for CO oxidation reactions
(Fig. 30) [115–117]. The synthesized clusters contained not only stable Sn(IV) but
also metastable divalent Sn(II) species, which act as an active site for CO adsorption.
The increased ratio of Sn(II)/Sn(IV) that decreased the particle size enhanced CO
oxidation reactivity.
Fig. 27 (a) Dependence of kinetic current density on the weight of platinum modified on a glassy
carbon electrode for Pt n @DPAG4-TPM (n ¼ 12, 28, or 60) and for commercially available Pt
catalyst. (b) Comparison of catalytic performances normalized by the weight of Pt n clusters and the
Pt/C catalysts. Adapted with permission from [111]. Copyright 2014 American Chemical Society
Fig. 28 Hydrogenation of low-reactive olefins and reductive amination of aldehydes catalyzed by
Pt 12 @DPAG4-TPM/GMC
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M. Tanabe and K. Yamamoto
accumulation of SnCl 2 to a DPA-TPM dendrimer, loaded into mesoporous silica,
followed by chemical reduction and calcination under air to remove the dendritic
template. The Sn n O x clusters are catalytically active for CO oxidation reactions
(Fig. 30) [115–117]. The synthesized clusters contained not only stable Sn(IV) but
also metastable divalent Sn(II) species, which act as an active site for CO adsorption.
The increased ratio of Sn(II)/Sn(IV) that decreased the particle size enhanced CO
oxidation reactivity.
Fig. 27 (a) Dependence of kinetic current density on the weight of platinum modified on a glassy
carbon electrode for Pt n @DPAG4-TPM (n ¼ 12, 28, or 60) and for commercially available Pt
catalyst. (b) Comparison of catalytic performances normalized by the weight of Pt n clusters and the
Pt/C catalysts. Adapted with permission from [111]. Copyright 2014 American Chemical Society
Fig. 28 Hydrogenation of low-reactive olefins and reductive amination of aldehydes catalyzed by
Pt 12 @DPAG4-TPM/GMC
154
M. Tanabe and K. Yamamoto