“…The specific surface area and pore size distribution of the Fe 3 O 4 @SiO 2 @GA/Cu and Fe 3 O 4 @GA/Cu catalysts were measured (Figure a,b). The adsorption isotherms were typical type-IV curves at relative pressures between 0.5 and 1, indicating that the structures contained mesopores. , Notably, the structure contained mesopores; therefore, the substrate molecules were easily transported in the catalyst, and the hydrothermal temperature used for fabricating the catalysts was a crucial factor in determining the pore structure . Thus, Fe 3 O 4 @SiO 2 @GA/Cu catalysts prepared at different hydrothermal temperatures, for example, 170, 180, and 190 °C were studied.…”