Nanoscale Precursor Distribution by Microfluidization for Scalable Production of Highly Efficient Thermocatalysts

Abstract

The preparation of two-dimensional (2D) materials often requires complicated exfoliation procedures having low yields. The exfoliated nanosheets are prone to thermal aggregation and unsuitable for thermocatalysis. Herein, a scalable approach produces 2D catalyst precursors well-distributed and mixed at the nanoscale. Using continuous microfluidization and single-layer layered double hydroxide (LDH) synthesis, the prepared suspension contained exfoliated hexagonal boron nitride (h-BN) nanosheets and single-layer LDHs. The increased contact area between h-BN and LDHs enables the formation of highly dispersed MnCoAl mixed metal oxide nanoparticles anchored on h-BN nanosheets after calcination. In the selective catalytic reduction of NOx with NH3 (NH3-SCR, a representative thermocatalytic application), this nanocomposite demonstrates a record turnover frequency of 0.772 h−1 among reported Mn-based NH3-SCR catalysts, with high NOx conversion and high N2 selectivity at low temperatures. By creating 2D precursors mixed at the nanoscale, this new synthetic approach can realize the scalable production of highly efficient thermocatalysts.