Photoreduction of CO2 using sol-gel derived titania and titania-supported copper catalysts

被引:493
作者
Tseng, IH [1 ]
Chang, WC [1 ]
Wu, JCS [1 ]
机构
[1] Natl Taiwan Univ, Dept Chem Engn, Taipei 10617, Taiwan
关键词
photocatalytic reduction; carbon dioxide; titanium dioxide; sol-gel; copper;
D O I
10.1016/S0926-3373(01)00322-8
中图分类号
O64 [物理化学(理论化学)、化学物理学];
学科分类号
070304 ; 081704 ;
摘要
Carbon dioxide was photocatalytically reduced to produce methanol in an aqueous solution using 254 nm UV irradiation. Titania and Cu-loaded titania were synthesized by an improved sol-gel method using a homogeneous hydrolysis technique. The grain size of TiO2 and Cu/TiO2 were uniform and average diameters were approximately 20 nm. Photocatalytic reduction was conducted in a quartz reactor with a UV lamp irradiating at the center. XPS analysis reveals that Cu 2P(3/2) is 933.4 eV indicating primary CU2O species on the TiO2 Supports. EDX and XPS revealed that most copper clusters were on the TiO2 surface. The optimum amount of copper loading was 2.0 wt.% for the highest dispersion among catalysts. The methanol yield of 2.0 wt.% CU/TiO2 was 118 mumol/g following 6 It of UV illumination. The yield was much higher than those of sol-gel TiO2 and Degussa P25, whose yields were 4.7 and 38.2 mumol/g, respectively. The methanol yield reached a steady-state 250 mumol/g after 20 h of irradiation. Experimental results indicated that the methanol yield was significantly increased by adding NaOH. The caustic solution dissolved more CO2 than did pure water. In addition, the OH- in aqueous solution also served as a strong hole scavenger. The redistribution of the electric charge and the Schottky barrier of Cu and TiO2 facilitates electron trapping via supported Cu. The photocatalytic efficiency of Cu/TiO2 was markedly increased because of the lowering the re-combination probability for hole-electron pairs. The highest quantum and energy efficiencies achieved were 10 and 2.5%, respectively. (C) 2002 Elsevier Science B.V. All rights reserved.
引用
收藏
页码:37 / 48
页数:12
相关论文
共 20 条
[1]   PHOTOCATALYTIC HYDROGENATION OF CH3CCH WITH H2O ON SMALL-PARTICLE TIO2 - SIZE QUANTIZATION EFFECTS AND REACTION INTERMEDIATES [J].
ANPO, M ;
SHIMA, T ;
KODAMA, S ;
KUBOKAWA, Y .
JOURNAL OF PHYSICAL CHEMISTRY, 1987, 91 (16) :4305-4310
[2]   The use of O1s charge referencing for the X-ray photoelectron spectroscopy of Al/Si, Al/Ti and Al/Zr mixed oxides [J].
Bhattacharya, AK ;
Pyke, DR ;
Reynolds, R ;
Walker, GS ;
Werrett, CR .
JOURNAL OF MATERIALS SCIENCE LETTERS, 1997, 16 (01) :1-3
[3]  
CHANG HF, 1994, J MOL CATAL, V94, P233
[4]   THE MEASUREMENT OF COPPER SURFACE-AREAS BY REACTIVE FRONTAL CHROMATOGRAPHY [J].
CHINCHEN, GC ;
HAY, CM ;
VANDERVELL, HD ;
WAUGH, KC .
JOURNAL OF CATALYSIS, 1987, 103 (01) :79-86
[5]  
Halmann M., 1983, PHOTOCHEMICAL FIXATI
[6]   PHOTOCATALYZED REDUCTION OF CO2 IN AQUEOUS TIO2 SUSPENSION MIXED WITH COPPER-POWDER [J].
HIRANO, K ;
INOUE, K ;
YATSU, T .
JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY A-CHEMISTRY, 1992, 64 (02) :255-258
[7]   PHOTOREDUCTION OF CARBON-DIOXIDE USING CHALCOGENIDE SEMICONDUCTOR MICROCRYSTALS [J].
INOUE, H ;
MORIWAKI, H ;
MAEDA, K ;
YONEYAMA, H .
JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY A-CHEMISTRY, 1995, 86 (1-3) :191-196
[8]   Photocatalytic reduction of high pressure carbon dioxide using TiO2 powders with a positive hole scavenger [J].
Kaneco, S ;
Shimizu, Y ;
Ohta, K ;
Mizuno, T .
JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY A-CHEMISTRY, 1998, 115 (03) :223-226
[9]   PHOTOCHEMICAL REDUCTION OF CARBON-DIOXIDE TO METHANOL USING ZNS MICROCRYSTALLITE AS A PHOTOCATALYST IN THE PRESENCE OF METHANOL DEHYDROGENASE [J].
KUWABATA, S ;
NISHIDA, K ;
TSUDA, R ;
INOUE, H ;
YONEYAMA, H .
JOURNAL OF THE ELECTROCHEMICAL SOCIETY, 1994, 141 (06) :1498-1503
[10]   PHOTOSYNTHETIC EFFICIENCY OPTIMIZATION STUDIES WITH THE MACROALGA GRACILARIA-TIKVIHAE - IMPLICATIONS FOR CO2 EMISSION CONTROL FROM POWER-PLANTS [J].
LAWS, EA ;
BERNING, JL .
BIORESOURCE TECHNOLOGY, 1991, 37 (01) :25-33