Shun-Cheng Lee

Developing efficient catalysts for low-temperature O₂ activation is critical for energy-efficient heterogeneous catalysis, yet designing highly active and accessible active sites remains a formidable challenge. Here, we construct a new type of zero-valent platinum single atoms (Pt⁰ SAs) on two-dimensional Co₃O₄ through a feasible low-temperature reduction strategy. By eliminating oxygen coordination, we induce strong Pt−Co electronic interactions and optimize the Pt 5 d band center, promoting electron donation that strengthens O₂ activation. In contrast, conventional high-valent Pt⁴⁺ SAs, which rely on oxygen vacancy formation, exhibits weaker O₂ activation. Consequently, Pt⁰ SAs achieves a 9.3-fold higher turnover frequency in toluene oxidation than does the Pt⁴⁺ SAs at 140 °C (the temperature at which a toluene conversion efficiency of 90% is achieved). This work highlights electronic modulation in optimizing O₂ activation and affords a strategy for designing highly efficient zero-valent single atom catalysts.

Solar-driven conversion of CO₂ and H₂O into chemicals is a promising strategy, while achieving simultaneous and efficient CO₂ reduction and H₂O oxidation remains challenging. Here, inspired by the role of plastoquinone in temporarily storing electrons during natural photosynthesis, we design a silver-modified tungsten trioxide (Ag/WO₃) that functions as a charge reservoir through reversible W⁶⁺/W⁵⁺ transitions under irradiation. When coupled with various active components, Ag/WO₃ significantly enhances their CO₂ conversion performance, indicating the universality of this strategy. Specifically, coupling Ag/WO₃ with cobalt phthalocyanine (CoPc), the CoPc/Ag/WO₃ catalyst achieves a CO production rate of ~1.5 mmol g_CoPc⁻¹ h⁻¹, representing a 100-fold enhancement over pure CoPc. Mechanistic studies reveal that electrons stored in Ag/WO₃ efficiently scavenge photogenerated holes from CoPc, thereby maintaining a high electron density at CO₂ reduction sites of CoPc. This work establishes a bioinspired charge reservoir strategy for efficient CO₂ photoreduction, providing a universal approach to solar fuel production.

Oceanic and anthropogenic processes, such as sea-salt emissions and combustion activities, release substantial amount of reactive chlorine into the troposphere, affecting air quality, ozone depletion, and climate change. However, distinguishing between these sources for reactive chlorine remains challenging. Here, we establish isotopic constraints on the origin of tropospheric reactive chlorine using chemical ionization mass spectrometry to analyze nitryl chloride (ClNO ₂ ). Field observations from four regions in China reveal a much broader isotopic value (δ ³⁷ Cl) range for ClNO ₂ (−21 to +39‰) than previously documented for Earth’s chlorine reservoirs. Notably, significant δ ³⁷ Cl differences for ClNO ₂ from sea-salt emissions (−9 ± 4‰) and anthropogenic combustion sources (+20 ± 7‰) were identified. These distinct isotopic signatures, combined with field data, highlight the important role of oceanic chlorine in air pollution, with its chemical cycling affecting not only coastal regions but also extending into inland areas. This research advances our understanding of chlorine’s behavior and cycling in the troposphere.

Solid atmospheric particulates can act as heterogeneous drivers for gas loss and particle aging during haze episodes. Observational and experimental evidence reveals an unidentified competitive mechanism involving transition metal ions (TMIs) that catalyze the heterogeneous oxidation of isoprene. Hydroxyl radicals (OH) were generated through the reaction of singlet oxygen (O(¹D)) with molecular water at the surface of earth‐abundant manganese (Mn) nanoparticles. The energy threshold for OH production was minimized to 213 kJ mol⁻¹ in the presence of alkali K⁺ ions, significantly lower than the 392 kJ mol⁻¹ required for ozone photolysis. The rapid loss of isoprene (1.60 × 10⁻² s⁻¹) for the particulate mixtures resulted in the formation of approximately 70% C₁–C₄ carbonyl oligomers via interfacial binding modes, which promoted particle growth. This contrasts with the higher yields of C₅ products typically observed in gas‐phase reactions of isoprene with OH radicals. The findings could enhance the understanding of severe haze formation, particularly under complex air pollution conditions.

The Tibetan Plateau (TP) is highly susceptible to climate change, and nitrogen-containing organic compounds (NOCs) in fine particulate matter (PM_2.5) represent one of the largest uncertainties with respect to their impact on the climate in high-altitude areas. Previous studies have shown that NOCs play a vital role in the nitrogen budget of PM_2.5. However, our understanding of the composition and sources of NOCs in PM_2.5, particularly in the TP, is limited. Here, we aim to enhance our understanding of NOCs in the TP region by examining their identification, concentration levels, sources, and origins. We conducted field sampling at a regional background sampling site in Gaomeigu, in the southeastern margin of the TP from 11 March to 13 May 2017, followed by laboratory analysis of the NOCs collected on the filters. The daily mass concentrations of NOCs ranged from 714.4 to 3887.1 ng m⁻³, with an average of 2119.4 ± 875.0 ng m⁻³ during the campaign. This average concentration was approximately 40 % higher than that reported at a typical regional site in the North China Plain (NCP), highlighting a more significant presence of NOCs in the Tibetan area. Biomass burning and secondary sources were identified as the major contributors to total NOCs. This was further substantiated by a regional air quality model, which indicated that over 80 % of the aerosol in the southeast of the TP originated from neighboring countries. This study improves our understanding of NOCs' contribution to PM_2.5 in the TP and their potential impacts on climate stability in high-altitude areas.

The Tibetan Plateau (TP) is highly susceptible to climate change and the nitrogen-containing organic compounds (NOCs) in fine particulate matter (PM_2.5) represent one of the large uncertainties in affecting the climate in high-altitude areas. Previous studies have shown that NOCs play a vital role in the nitrogen budget of PM_2.5. However, our understanding of the composition and sources of NOCs in PM_2.5, particularly in TP, is limited. Here, we aim to enhance our understanding of NOCs in the TP region by examining their identification, concentration levels, sources, and origins. We conducted field sampling at a regional background sampling site in Gaomeigu, in the southeastern margin of TP from March 11^th to May 13^th in 2017. The daily mass concentrations of NOCs ranged from 714.4 to 3887.1 ng m^-3, with an average of (2119.4 ± 875.0 ng m^-3) during the campaign. This average concentration was approximately 40 % higher than that reported at a typical regional site in the North China Plain (NCP), highlighting a more significant presence of NOCs in the Tibetan area. Biomass burning and secondary sources were identified as the major contributors to total NOCs. This was further substantiated by a regional air quality model, which indicated that over 80 % of the aerosol in the southeast of TP originated from neighboring countries. This study enhances our understanding of NOCs’ contribution to PM_2.5 in TP and their potential impacts on the climate stability in high-altitude areas.