Hydroisomerization catalysts with enhanced metal charge density prepared by a novel low temperature loading method

Bifunctional catalysts, consisting of metal and acid sites, can be applied in the alkane hydroisomerization reaction, and the process of dehydrogenation and hydrogenation at the metal sites can balance the isomerization and cracking routes, carbocation rearrangement at acidic sites affecting the hydroisomerization performance. Metals are traditionally prepared at high temperature which results in metal agglomeration. To address this drawback, a low-temperature method for catalyst loading is proposed. The method provides catalysts with smaller particle sizes and higher dispersion to prevent metal agglomeration. Specifically, when the loading capacity of metal Pt is 0.3 wt%, this method results in both single atoms and metal clusters within the catalyst. And the catalyst shows a balanced metal-acid function once capacity for Pt loading increased to 0.5 wt%. Moreover, the electron density of Pt following metal loading on g-C₃N₄ support increased, and the turnover frequency (TOF) of each metal site also increased with the rise of n_Pt/n_A. Furthermore, it is noted that the catalyst prepared by low-temperature loading shows significant increased hydroisomerization activity and selectivity compared to those prepared with the traditional method, with an isomer yield of up to 68.2 %.