Study of NH3-SCR Catalyst Combinations Based on Diesel Engine Exhaust Emission Mechanisms

Abstract

The overlap between the activity interval of a single catalyst and the exhaust gas temperature interval of several engines is small. In the industry, this problem is solved by increasing catalyst loadings. This has led to a certain amount of raw materials waste and increased catalyst production costs. In this study, Ce-W/Ti was introduced into Cu-SSZ-13 using solid phase grinding to change its activity range. Catalysts with different grinding ratios were subjected to small-sample performance experiments and characterization, and matching samples were selected by combining the results of the experiments with the emission characteristics of the MC07H diesel engine. World harmonized transient cycle (WHTC) and World harmonized steady-state cycle (WHSC) tests were conducted on the engine bench to investigate the causes of NO x concentration maxima during diesel engine operation using this catalyst combination strategy. The WHTC and WHSC emissions are 0.2464 and 0.1987 g/kWh. Based on the combined strategy, a performance match with diesel engines can be achieved while reducing the cost by $11/kg compared with the Cu-SSZ-13 catalyst, demonstrating the potential of the process for large-scale applications.