Environment and Conservation Fund - Towards Livable & Healthy City: Solar-Driven Exhaust Fume (NOx) Purification Engineering for Eco-Friendly Transportation and Electricity Generation in Hong Kong

Professor Phillips, David Lee   (Principal Investigator (PI))

Dr Du Lili   (Co-Investigator)

Dr Wang Wenchao   (Co-Investigator)

36

2023-12-01

1083000

Environment and Conservation Fund - Towards Livable & Healthy City: Solar-Driven Exhaust Fume (NOx) Purification Engineering for Eco-Friendly Transportation and Electricity Generation in Hong Kong

Solar-Driven Exhaust Fume (NOx); Eco-Friendly Transportation; Electricity Generation

Power System

ECF Project 109/2022

Environment and Conservation Fund 2022

2022

On-going

Urban nitrogen oxides (NOx­), and in particular NO and NO2, are burning issues for healthy life and the sustainable environment, which directly cause haze, acid rain, and photochemical smog. Due to the abundant N2 and O2 in inlet air, NOx are formed easily under the high-temperature combustion in engines, including steamships and vehicles. Up to now, the number of total licensed vehicles (e.g. private cars, taxis, public buses and goods vehicles) is greater than 800,000 in Hong Kong (data from VALID and Licensing Division). Navigation, road transport and electricity generation are three important sources (total reach to 81%) of NOx emission, accounting for 35%, 16% and 30% in 2019, respectively. Compare to conventional techniques (e.g. thermal catalysis, biotechnology and electrocatalysis), solar-driven photocatalysis as a ""green"" approach shows a remarkable advantage for the removal of NOx at the parts per billion (ppb) level with economic benefit and simplified device. However, as for the high-concentration of NOx (> 10 ppm) treatment in roadside and electric power stations, photocatalysis barely shows high efficiency due to the photon energy absorption efficiency and degradation rate. This proposal aims to definitely provide a sustainable solar-driven air purification technology to improve the outdoor air quality, particularly for local road transport (i.e., private cars, taxis and public buses) and electric power stations in Hong Kong. Developing functionalized catalysts by porosity engineering, 0D-2D materials (for example, COFs, MOFs and g-C3N4) and atomic tuning strategy (for instance, single atom and atomic defects) to enhance NOx absorption, decrease energy barrier and enrich catalytic sites, respectively. In addition, to figure out the key step of photocatalytic NOx conversion, we propose to employ in-situ and operando technologies (e.g., femtosecond absorption spectroscopy and nanosecond Raman spectroscopy) for monitoring active species transfer and survival processes. As a result, the advanced materials and technology will be commercialized and exhibited via patents, publications and international academic conferences. Finally, a novelty Solar Energy Conversion Center will be established in Hong Kong to develop advanced materials and technological pathways to an eco-friendly industry.Our research group possesses good experience in photocatalytic reactions (particularly in solar-to-chemical conversion), functional materials synthesis (e.g. g-C3N4, WO3 and TiO2) and in-situ photochemical processes monitoring via time-resolved spectroscopy. Solar-driven NOx gas oxidization, as a green and cost-effective technology, can effectively reduce environmental damage with considerable economic benefit in Hong Kong.