TY - JOUR
T1 - Ordered mesoporous Au/TiO2 nanospheres for solvent-free visible-light-driven plasmonic oxidative coupling reactions of amines
AU - Yang, Jingling
AU - Mou, Chung Yuan
N1 - Funding Information:
This work was supported by National Taiwan University. Jingling Yang was supported by a postdoctoral fellowship of Ministry of science and technology (MOST). We thank Ching-Yen Lin and Ya-Yun Yang at Instrument Center of National Taiwan University for assistance with SEM, and Dr. Xianfeng Yang at Analytical and Testing Center of South China University of Technology for helping in high-magnification TEM. We thank Y.W. Wang, K.C. Kao, Fu-Yu Tsai and S. Runa for helps in this work.
Funding Information:
This work was supported by National Taiwan University . Jingling Yang was supported by a postdoctoral fellowship of Ministry of science and technology (MOST) . We thank Ching-Yen Lin and Ya-Yun Yang at Instrument Center of National Taiwan University for assistance with SEM, and Dr. Xianfeng Yang at Analytical and Testing Center of South China University of Technology for helping in high-magnification TEM. We thank Y.W. Wang, K.C. Kao, Fu-Yu Tsai and S. Runa for helps in this work. Appendix A
Publisher Copyright:
© 2018 Elsevier B.V.
PY - 2018/9/5
Y1 - 2018/9/5
N2 - Imines are important intermediates for the synthesis of fine chemicals and pharmaceuticals. Design of a “green” oxidation catalyst to promote the direct oxidation of amines to imines by dioxygen have attracted great attention. Herein, we designed a catalyst of ordered mesoporous Au/M-TiO2 nanoparticles using a template-based approach. The as-prepared Au/M-TiO2 nanoarrays of anatase crystalline structure, with high specific surface area (222 m2/g), small pore size (∼2.1 nm) and ordered arrangements, gave dense array of ultrasmall pore-confined gold nanoparticles. The mesoporous Au/M-TiO2 exhibits particularly high visible light activity for photocatalytic selective aerobic oxidation of benzylamine to N-benzylidene benzylamine in a green approach by utilizing dioxygen as an oxidant in solvent-free conditions. The yield of N-benzylidene benzylamine can reach 1.73 mmol (TOF = 178.6 h−1, based on Au) in Au/M-TiO2 system, which is 1.5 and 1.6 times higher than that of the Au/P25 and Au/Acros anatase photocatalysts, respectively. Furthermore, we can also achieve high yield of N-benzylidene benzylamine (1.30 mmol, TOF = 134.2 h−1, based on Au) in air atmosphere. The confinement effect of the mesopores in Au/M-TiO2 facilitate the formation of [rad]O2− radicals and make the bi-molecular reaction highly preferred for promoting the high selectivity and conversion in plasmonic photocatalysis. Meanwhile, the Au/M-TiO2 with mesoporous structure can facilitate the efficient contact between the solvent and the nanomaterial, while possessing sufficient interfacial area for active oxidation reactions. This work paves a promising way to develop visible light-responsive TiO2-based photocatalysts with high specific surface area for highly efficient green oxidative organic synthesis.
AB - Imines are important intermediates for the synthesis of fine chemicals and pharmaceuticals. Design of a “green” oxidation catalyst to promote the direct oxidation of amines to imines by dioxygen have attracted great attention. Herein, we designed a catalyst of ordered mesoporous Au/M-TiO2 nanoparticles using a template-based approach. The as-prepared Au/M-TiO2 nanoarrays of anatase crystalline structure, with high specific surface area (222 m2/g), small pore size (∼2.1 nm) and ordered arrangements, gave dense array of ultrasmall pore-confined gold nanoparticles. The mesoporous Au/M-TiO2 exhibits particularly high visible light activity for photocatalytic selective aerobic oxidation of benzylamine to N-benzylidene benzylamine in a green approach by utilizing dioxygen as an oxidant in solvent-free conditions. The yield of N-benzylidene benzylamine can reach 1.73 mmol (TOF = 178.6 h−1, based on Au) in Au/M-TiO2 system, which is 1.5 and 1.6 times higher than that of the Au/P25 and Au/Acros anatase photocatalysts, respectively. Furthermore, we can also achieve high yield of N-benzylidene benzylamine (1.30 mmol, TOF = 134.2 h−1, based on Au) in air atmosphere. The confinement effect of the mesopores in Au/M-TiO2 facilitate the formation of [rad]O2− radicals and make the bi-molecular reaction highly preferred for promoting the high selectivity and conversion in plasmonic photocatalysis. Meanwhile, the Au/M-TiO2 with mesoporous structure can facilitate the efficient contact between the solvent and the nanomaterial, while possessing sufficient interfacial area for active oxidation reactions. This work paves a promising way to develop visible light-responsive TiO2-based photocatalysts with high specific surface area for highly efficient green oxidative organic synthesis.
KW - Au/TiO
KW - Confinement effect
KW - Plasmonic photocatalysis
KW - Solvent-free
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U2 - 10.1016/j.apcatb.2018.02.054
DO - 10.1016/j.apcatb.2018.02.054
M3 - Article
AN - SCOPUS:85044851894
SN - 0926-3373
VL - 231
SP - 283
EP - 291
JO - Applied Catalysis B: Environmental
JF - Applied Catalysis B: Environmental
ER -