Reducing atmospheric pollutants and greenhouse gas is one of the pressing needs for environmental sustainability. Interfacial chemistry plays a crucial role in addressing this challenge. The first part of this thesis focuses on the uptake and chemistry of nitrogen dioxide (NO2), a significant atmospheric pollutant, on two major dust components – α-quartz and calcite. Through first principle dynamic simulations under water constrained conditions, (1) on the surface of hydroxylated α-quartz, NO2 is initially absorbed as HONO, then barrierlessly converts to nitric acid, and can possibly further dissociate into NO and OH radicals. (2) on the surface of calcite, NO2 directly converts into HONO without being further photoactivated. Notably, in both cases, the formation of HONO does not call for the dimerization of NO2, the traditional and most accepted mechanism, yet questionable even in highly polluted areas. These findings have provided robust theoretical support for understanding the atmospheric fate of NO2 and offer valuable insights for developing novel technology to remove NO2.Parallel studies highlight the design of a novel MOF catalyst, featuring asymmetric Ni/Cu sites stabilized by a pyrazolate linker (noted as Cu1Ni-BDP) with exceptional selectivity and stability for the electrochemical reduction of CO2 to ethylene. Through density functional theory, a mapping of the energy profile along the key reaction pathway from *CO to *C2H4 is presented. Among three candidates with distinct catalytic sites, Cu1Ni-BDP exhibited the moderate binding energy of *CO at -2.94 eV. In the critical rate-limiting steps of *COH-*COH and *CH2-CH towards C2+ products, Cu1Ni-BDP demonstrated the lowest Gibbs free energy of -0.08 eV and 0.01 eV, respectively, suggesting the asymmetric Ni/Cu sites can effectively enhance the formation and absorption of symmetric intermediates, thereby promoting CO2 to C2+ product with higher selectivity, in line with experimental results. Herein, a deep understanding and exploitation of the interfacial chemistry is pivotal in elucidating the conversion mechanism of NO2 to provide solid theoretical support in pollutant control and guiding an important strategy for designing more efficient and selective catalysts to utilize greenhouse gas effectively.