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In selective catalytic reduction (SCR) technology, aggregation of the catalyst generally degrades the performance for converting nitrogen oxides into harmless gases. To avoid such performance degradation and to achieve a noticeable improvement in the SCR performance, good dispersion of the catalyst on the support is required. In this study, we synthesized MnO x −CeO x catalytic nanoparticles on surface-modified supports and studied the dispersion behavior of the catalyst on the support. Hexagonal boron nitride (h-BN) was adopted as the catalyst support, which was modified by catalytic etching to create vacancy defects on the support. To enhance the effect of surface modification, the etched h-BN flakes were exfoliated by ultrasonication treatment and were further modified by controlling the pH of the surface. As a consequence of surface modification, the specific surface area increased from 41.89 to 67.29 m 2 /g. Microscopic analysis revealed that the size of the catalytic particles was mainly distributed with an average of 5 nm in modified h-BN. Surprisingly, the conversion efficiency of NO x gas approached 97% at a relatively low temperature (175−225 °C) when surface-modified h-BN was used as the support. The noticeable improvement in the catalytic performance is attributed to the high dispersion of active materials with the use of a porous support.

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