부산대학교 도서관

The Co3O4nanoparticles, dominated by a catalytically active (110) lattice plane, were synthesized as a low-temperature NOxadsorbent to control the cold start emissions from vehicles. These nanoparticles boast a substantial quantity of active chemisorbed oxygen and lattice oxygen, which exhibited a NOxuptake capacity commensurate with Pd/SSZ-13 at 100 °C. The primary NOxrelease temperature falls within a temperature range of 200–350 °C, making it perfectly suitable for diesel engines. The characterization results demonstrate that chemisorbed oxygen facilitate nitro/nitrites intermediates formation, contributing to the NOxstorage at 100 °C, while the nitrites begin to decompose within the 150–200 °C range. Fortunately, lattice oxygen likely becomes involved in the activation of nitrites into more stable nitrate within this particular temperature range. The concurrent processes of nitrites decomposition and its conversion to nitrates results in a minimal NOxrelease between the temperatures of 150–200 °C. The nitrate formed vialattice oxygen mainly induces the NOxto be released as NO2within a temperature range of 200–350 °C, which is advantageous in enhancing the NOxactivity of downstream NH3-SCR catalysts, by boosting the fast SCR reaction pathway. Thanks to its low cost, considerable NOxabsorption capacity, and optimal release temperature, Co3O4demonstrates potential as an effective material for passive NOxadsorber applications.