NOx emission reduction reaction of ammonia-hydrogen with self-sustained pulsating oscillations

•NOx emission reduction reaction of NH3-H2 with self-excited pulsating oscillations is numerically studied.•Effects of the NH3-H2 fuel and H2 mass fraction on producing pulsating oscillations and NOx are examined.•Mode-switching is observed as the flow rate of the blended fuel of NH3-H2 is varied.•Intermittency oscillations and nonlinear combustion-driven oscillations are successfully generated.•Applying heat exchangers to dampen pulsating oscillations and reducing NOx is explored.