Photocatalytic hydrogen production from methanol over Nd/TiO2
M. Edelmannováa, Kuan Yu Linb, Jeffrey Chi-Sheng Wub, Ivana Troppováa, Libor Čapekc, Kamila Kočía
aInstitute of Environmental Technology, VŠB-Technical University of Ostrava, 17. listopadu 15/2172, Ostrava, 70833, Czech republic,
bNational Taiwan University, Catalyst Laboratory of the National Taiwan University, Taipei, 10617, Taiwan
cFaculty of Chemical Technology, University of Pardubice, Studentská 95, 532 10 Pardubice, Czech Republic.
Economic development causes an increase in energy consumption and a conbsequent increase environmental pollution. CO2 emissions have increased by 1.9 % per year over the last three decades, which is closely related to the increased use of fossil fuels. Addressing the challenge of increasing energy consumption in conjunction with environmental threats. It is a challenge for the whole of society to solve the issue of increasing energy consumption in conjunction with environmental threats. Photocatalytic reduction of CO2 is one of the interesting ecological methods of reducing CO2 emissions in the atmosphere, using sunlight as the radiation source.
In this work, copper-doped TiO2-based photocatalysts (1, 3 and 5 wt.% CuO) were investigated for the photocatalytic reduction of CO2 and the experiments were carried out in two reactions (liquid and gaseous phases) with the addition of hydrogen. In the liquid phase reaction, the highest yields of CH4 were found in the presence of 5 wt.% CuO/TiO2 and pure TiO2. The activity of photocatalysts was mainly influenced by two factors: the availability of active sites (SBET) and the output work needed to release the electron from the surface (work function). The lowest energy for electron release at the wavelength of 254 nm and the highest specific surface area (119 and 66 m2/g) was found for TiO2 and 5 wt.% CuO/TiO2. In the gas phase reaction, CH4 and CO yields decreased in the order: TiO2 > 3 wt.% CuO / TiO2 > 5 wt.% CuO / TiO2 > 1 wt.% CuO / TiO2. Conducting the experiment in different phases does not seem to change the mechanism of photocatalytic reduction of CO2, but the location of the photocatalyst in the different phases can accelerate the different reaction pathways.