A scalable solar-based thermal catalytic purification battery for day and night heating and HCHO removal

The excessive reliance on air conditioning for comfortable indoor environment, due to over 80% of individuals’ time being spent indoors, with nighttime occupancy reaching 100%, leads to considerable energy consumption and sick building syndrome. A promising solution to simultaneously tackle these challenges involves harnessing solar thermal energy during the day to facilitate the all-day heating and removal of indoor pollutants. Here, a proof-of-concept solar-based Trombe-wall thermal catalytic purification battery (TCPB), integrating multi-layer-design phase changing materials (PCM) and room-temperature thermal catalysts (RTTC), is reported for the first time. The density functional theory simulation shows that RTTC stoichiometric surface (100) occurs abundant active sites, and reduced surface (100) facilitates adsorption/activation of oxygen in atmosphere, thereby enhancing room-temperature formaldehyde oxidation activity. Based on the designed prototype, two adoptable operation modes can be flexible on residential and office buildings, maintaining charging and/or discharging in daytime and discharging in nighttime to realize all-day heating and purification. With calculation of verified mathematical model, the combination of RTTC and PCM technology exhibited excellent heating and purification performance. The amount of clean air stored during the day was 7.12 m3 and the amount of clean air at night could be 39.39 m3. The heat absorption efficiency of TCPB prototype could reach 40.85 %, and the heat release efficiency was 58.08 %.