The simultaneous purification of PM and NOx in diesel engine exhausts over a single 3DOM Ce0.9−xFe0.1ZrxO2 catalyst†
A novel catalytic purification process SCRPF (selective catalytic reduction and particulate filter) over a 3DOM catalyst was designed and used for the simultaneous removal of PM (particulate matter) and NOx from diesel engine exhausts. It is a combination of DPF and SCR of NOx reduction technology advantages. The catalytic purification taking place over a SCRPF reactor is cost-efficient. The contact between the solid PM and the catalyst active sites is process intensified by the 3DOM unique structure. The 3DOM Ce0.85Fe0.1Zr0.05O2 catalyst gave a maximum concentration of CO2 at 415 °C for PM combustion and showed 100% NO conversion in the temperature range of 365–503 °C. The different Ce/Zr ratio and the introduction of Fe species present various Ce3+/Ce4+, abundant oxygen vacancies, excellent reducibility and sufficient acid sites in the catalyst, which are effective for the simultaneous removal of PM and NOx. The use of a low cost catalyst may be more desirable.