Periodic Reporting for period 1 - NOMTGCS (Noble Metal Loaded Oxygen-deficient Mesoporous Tungsten Trioxide for Green Catalysis under Solar Light)
Reporting period: 2019-03-05 to 2021-03-04
Current synthetic methodologies in chemical industry must be significantly improved to enable the production of many chemicals, such as H2O2 which is used in the manufacture of organic peroxide, through environmentally friendly and sustainable processes. These improvements should both satisfy the increasing demands for industrial chemicals and solve the accompanying energy and environmental problems. One of the main challenges for establishing a sustainable society is to simulate natural photosynthesis and develop effective photocatalysts for various chemical transformations under solar light, which is almost never exhaustible. Chemists need to develop stable, efficient photocatalysts for chemical reaction processes promoted by solar light, which will greatly contribute to science and our futures.
The four principal objectives of this project: (1) To design and synthesize novel efficient photocatalysts based on oxygen deficient mesoporous WO3 supported Au, Pd or Au-Pd nanoparticles (M@odm-WO3; M=Au, Pd, or Au-Pd) (WP1); (2) To use the as-prepared photocatalysts in the liquid phase synthesis of 4 hydrogen peroxide from water and molecular oxygen without the usage of hydrogen gas under solar light irradiation (WP2); (3) To directly perform oxidation of alcohols with hydrogen peroxide in-situ generated under solar light in the presence of M@odm-WO3 (WP2); (4) To oxidize primary carbon-hydrogen bonds in toluene with molecular oxygen under solar light catalyzed by the as-prepared M@odm-WO3 (WP2).
After the fellowship is completed, we have successfully realized this four project objectives. We have developed an efficient Pd-MoO3 catalyst for highly selectively methane oxidation to methanol under simulated solar light irradiation. Besides, the fellowship has highly beneficial to establish the fellow as an independent researcher, and new career perspectives are achieved for a faculty position. Various outreach activities have been designed and done, which strengthen the impact on solar light photocatalysis and energy issues.
The four principal objectives of this project: (1) To design and synthesize novel efficient photocatalysts based on oxygen deficient mesoporous WO3 supported Au, Pd or Au-Pd nanoparticles (M@odm-WO3; M=Au, Pd, or Au-Pd) (WP1); (2) To use the as-prepared photocatalysts in the liquid phase synthesis of 4 hydrogen peroxide from water and molecular oxygen without the usage of hydrogen gas under solar light irradiation (WP2); (3) To directly perform oxidation of alcohols with hydrogen peroxide in-situ generated under solar light in the presence of M@odm-WO3 (WP2); (4) To oxidize primary carbon-hydrogen bonds in toluene with molecular oxygen under solar light catalyzed by the as-prepared M@odm-WO3 (WP2).
After the fellowship is completed, we have successfully realized this four project objectives. We have developed an efficient Pd-MoO3 catalyst for highly selectively methane oxidation to methanol under simulated solar light irradiation. Besides, the fellowship has highly beneficial to establish the fellow as an independent researcher, and new career perspectives are achieved for a faculty position. Various outreach activities have been designed and done, which strengthen the impact on solar light photocatalysis and energy issues.
Firstly, We prepare efficient nanoscale MoO3 supported Pd catalyst by hydrothermal synthesis and light reduction process. After that, the hydrogen peroxide generated from water without the usage of hydrogen gas under solar light irradiation was extensively studied on Pd/MoO3 catalyst. It was found water molecules can be oxide into H2O2 by photo-generated holes in MoO3 under simulated solar light irradiation. Then we use the in-situ generated H2O2 from MoO3 and Pd/MoO3 to perform oxidation of methanol into formic acid and methyl peroxide. It was found the the in-situ generated H2O2 from MoO3 can be decomposed into OH radicals and then oxide methanol into formic acid. However, the in-situ generated H2O2 from Pd/MoO3 is mainly decomposed into OOH radicals and then oxide methanol into methyl peroxide. Finally, we use the as-prepared Pd/MoO3 catalyst to oxidize primary carbon-hydrogen bonds in methane with water and molecular oxygen under solar light. It was found the in-situ generate H2O2 from water and molecular oxygen can selectively oxide the carbon-hydrogen bond in methane into carbon-oxygen hydrogen bond. It was found the primary product from methane oxidation by Pd-MoO3 is methanol and methyl peroxide. The combined selectivity to CH3OH and CH3OOH over an optimized Pd/MoO3 catalyst was 98.6% at 8 h time-on-line. The respective yield at 8 h of CH3OH and CH3OOH was measured at ca. 22 and 12 μmol L-1, achieving a combined product productivity rate of 42.5 μmol gcat-1·h-1.
After the fellowship, two papers are submitted in peer-reviewed international journals.
Songmei Sun, Nicholas F. Dummer, Takudzwa Bere, Alexandra J. Barnes, Greg Shaw, Mark Douthwaite, Samuel Pattisson, Richard Lewis, Nia Richards, David J. Morgan, Graham J. Hutchings, Selective photochemical oxidation of methane to methanol by palladium supported on molybdenum oxide under ambient conditions, submitted.
Songmei Sun, Alexandra J. Barnes, XiaoXiao Gong, Richard Lewis, Nicholas F. Dummer, Takudzwa Bere, Greg Shaw, Nia Richards, David J. Morgan, Graham J. Hutchings, Lanthanum modified Fe-ZSM-5 zeolites for selective methane oxidation with H2O2, submitted.
Songmei Sun, Nicholas F. Dummer, Takudzwa Bere, Alexandra J. Barnes, Greg Shaw, Mark Douthwaite, Samuel Pattisson, Richard Lewis, Nia Richards, David J. Morgan, Graham J. Hutchings, Selective photochemical oxidation of methane to methanol by palladium supported on molybdenum oxide under ambient conditions, submitted.
Songmei Sun, Alexandra J. Barnes, XiaoXiao Gong, Richard Lewis, Nicholas F. Dummer, Takudzwa Bere, Greg Shaw, Nia Richards, David J. Morgan, Graham J. Hutchings, Lanthanum modified Fe-ZSM-5 zeolites for selective methane oxidation with H2O2, submitted.