Photo reduction of CO2 to methanol using optical-fiber photoreactor
Photo reduction of CO2 to methanol using optical-fiber photoreactor
复制标题
DOI：
10.1016/j.apcata.2005.08.021
复制
发表时间：
2005-12-12
影响因子：
5.5
通讯作者：
Lai, CL
中科院分区：
文献类型：
--
作者：
Wu, JCS;Lin, HM;Lai, CL
二氧化碳等温室气体是全球变暖的主要原因。补救二氧化碳的最佳途径之一是利用光还原将其转化为碳氢化合物。在稳态光纤光反应器中，利用波长为365 nm的汞灯光催化还原CO2生成甲醇。设计并组装了由近120根CU/ tio2包覆光纤组成的光纤光反应器，实现了光在反应器内的均匀传输和扩散。采用浸涂法在光纤表面涂覆TiO2薄膜。采用热水解法制备负载cu的二氧化钛溶液。Cu/TiO2薄膜厚度为53 nm。涂层由直径接近14纳米的非常细小的球形颗粒组成。XRD谱图表明，所有TiO2和Cu/TiO2薄膜均为锐钛矿相。Cu/ TiO2的吸收边波长在367nm附近，相当于3.3 eV的带隙。TiO2表面最活跃的Cu物质是Cu2O簇，它们对甲醇的形成起着重要的作用。紫外辐照强度越大，甲醇收率越高。以1.2 wt.%-Cu/TiO2为催化剂，在CO2浓度为1.29 bar， H2O浓度为0.026 bar，平均停留时间为5000 s的16 W/cm(2) UV照射下，甲醇的最大速率为0.45 mu mol /g cat h。当Cu负载高于1.2 wt.%时，由于Cu2O团簇在TiO2表面的掩蔽作用，导致甲醇收率降低。通过关联实验数据，建立了Langmuir-Hinshelwood模型来描述其动力学行为。在光还原CO2的过程中，发现了最佳的水/CO2压力比。(c) 2005 Elsevier B.V.版权所有
Greenhouse gases such as CO2 are the primary cause of global warming. One of the best routes to remedy CO2 is to transform it to hydrocarbons using photo reduction. CO2 was photocatalytically reduced to produce methanol using a Hg lamp with wavelength 365 nm in a steady-state optical fiber photoreactor. The optical-fiber photoreactor, comprised of nearly 120 CU/TiO2-coated fibers, was designed and assembled to transmit and spread light uniformly inside the reactor. TiO2 film was coated on optical fiber using a dip-coating method. Cu-loaded titania solutions were prepared by a thermal hydrolysis method. The thickness of Cu/TiO2 film was 53 nm. The coating film consisted of very fine spherical particles with diameters of near 14 nm. The XRD spectra indicated the anatase phase for all TiO2 and Cu/TiO2 films. The wavelength of absorption edge on Cu/ TiO2 was near 367 nm, equivalent to a bandgap of 3.3 eV. The most active Cu species on TiO2 surface were Cu2O clusters, and they played an important role for the formation of methanol. The methanol yield increased with UV irradiative intensity. Maximum methanol rate was 0.45 mu mole/g cat h using 1.2 wt.%-Cu/TiO2 catalyst at 1.29 bar of CO2, 0.026 bar of H2O, and 5000 s mean residence time under 16 W/cm(2) UV irradiation. Higher than 1.2 wt.% Cu loading gave a lower rate of methanol yield because of the masking effect Of Cu2O clusters on the TiO2 surface. The Langmuir-Hinshelwood model was established by correlating experimental data to describe the kinetic behavior. An optimum pressure ratio of H2O/CO2 was found in the photo reduction of CO2 for maximum methanol yield. (c) 2005 Elsevier B.V. All rights reserved.