Photocatalytic Reduction of Carbon Dioxide to Methane in Gas Phase under UV Light Illumination using NiO/TiO2

• Main Authors: Pei-Chen Li, 李沛宸
• Other Authors: Yao-Hsuan Tseng
• Format: Others
• Language: en_US
• Published: 2018
• Online Access: http://ndltd.ncl.edu.tw/handle/4hp7uc

碩士 === 國立臺灣科技大學 === 化學工程系 === 106 === Photocatalytic reduction of carbon dioxide in gas phase by UV illumination and NiO/TiO2 process was studied under various initial carbon dioxide concentration, relative humidity, and coupled NiO dosage to evaluate the production of methane. In addition of that, the catalyst was detected by X-ray diffraction (XRD), field emission scanning electron (FE-SEM) microscope, UV-vis diffuse reflectance spectrometer (UV-DRS) and BET surface area analyzer. In this system, the initial carbon dioxide concentration is a significant factor to effect the photocatalytic reduction of carbon dioxide. As can be seen, this experiment is continuous reaction. And, this result presents that photoreduction of CO2 reacts quickly. After around 120 minutes, the carbon dioxide concentration keeps in the same concentration. The experimental results reveal that photoreduction of carbon dioxide using different loading of NiO on TiO2 surface can produce the highest amount of methane at initial 600 ppm carbon dioxide when the relative humidity is 10%. However, it also shows that initial carbon dioxide concentration limits the product formation once the CO2 concentration is too high. On the other hand, the relative humidity and coupled NiO dosage influence the production of methane. Results show that the production of methane increased with increasing relative humidity and couple NiO dosage. However, further addition of relative humidity and couple NiO dosage decrease the amount of methane because of the excessive of water content can influence the activated site and 20wt% NiO/TiO2 influence the pore size volume, energy gap and photocatalytic activity through BET surface area analyzer and UV-vis diffuse reflectance spectrometer (UV-DRS) result. In this study, the optimum operating conditions for photocatalytic reduction of carbon dioxide in gas phase by UV illumination and NiO/TiO2 process is as following: initial carbon dioxide concentration 600 ppm, 10wt% NiO/TiO2, and relative humidity 45%. According to the conditions, the maximum amount of methane is 400 ppm/(gcatalyst).