Visible light driven CO2 reduction to methanol by Cu-porphyrin impregnated mesoporous Ti-MCM-48
| Autor: | Asad Mumtaz, Mudassar Mumtaz, Bawadi Abdullah, M.I. Abdul Mutalib, Saad Nadeem, Maizatul Shima Shaharun |
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| Rok vydání: | 2018 |
| Předmět: |
Materials science
Analytical chemistry 02 engineering and technology 010402 general chemistry 021001 nanoscience & nanotechnology Condensed Matter Physics 01 natural sciences Atomic and Molecular Physics and Optics 0104 chemical sciences Electronic Optical and Magnetic Materials Catalysis chemistry.chemical_compound Light intensity chemistry Materials Chemistry Photocatalysis Methanol Physical and Theoretical Chemistry 0210 nano-technology Mesoporous material HOMO/LUMO Spectroscopy Visible spectrum BET theory |
| Zdroj: | Journal of Molecular Liquids. 272:656-667 |
| ISSN: | 0167-7322 |
| DOI: | 10.1016/j.molliq.2018.09.077 |
| Popis: | Mesoporous Ti-MCM-48 photocatalyst, with Si/Ti (wt/wt) ratio of 100, 50 and 25 was effectively applied for CO2 reduction into methanol under UV–visible light irradiation bearing mid gap energy states and Ti3+ sites. The bare Ti-MCM-48 with Si/Ti (wt/wt) ratio of 25 displayed highest photocatalytic methanol yield (85.88 μmol g−1 L−1) with a BET surface area of 1528 m2 g−1 and mid gap energy states as determined from the XPS analysis, compared to the other composite ratios. The Ti-MCM-48(25) impregnated with Cu-porphyrin (CuTPP) resulted in methanol yield of 297 μmol·g−1 under 33 mW·cm−2 simulated light intensity, using 0.1 M Na2SO3 in 0.1 M NaOH as supporting electrolytes, which is 3.45 times higher than the bare Ti-MCM-48(25) due to the visible light excitation of the porphyrin macrocycle and charge transition from the lowest occupied molecular orbital (LUMO) of CuTPP to the Ti3+ metal centers. Also, methanol yield was studied with CO2 gas-liquid mass transfer and mass transfer limitations prevailing in the reactor. Mass transfer limitation experiments revealed that metal loading, catalyst concentration, stirring speed and light intensity influence the methanol yield. |
| Databáze: | OpenAIRE |
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