On the Usability of Pt/Al ₂ O ₃ Catalysts for Exhaust Gas After Treatment in Ammonia Combustion Engines

Abstract Ammonia combustion engines for marine vessels are attractive due to zero CO 2 emissions but can lead to increased NH 3 and NO x fractions in the exhaust. An NH 3 /NO x ratio exceeding 1 renders conventional selective catalytic reduction systems inadequate for sufficient emission reduction. This study investigates whether the required stoichiometry can be achieved using Pt‐based oxidation catalysts, with only a portion of the exhaust stream directed through the catalyst in a simulated bypass configuration. Catalyst loading, platinum content, temperature, and space velocity were systematically varied with the aim of minimizing N 2 O formation concurrently. A Gaussian process model was employed to interpolate activity and selectivity between experimental data points. The study identifies the factors influencing N 2 O generation and discusses potential conditions for the application of Pt‐based catalysts in ammonia combustion systems.