“…Solution combustion methods have made outstanding contributions in the preparation of nanometer material [15,16]. Solution combustion methods have a series of superiorities in the preparation process, such as a relatively simple device, low cost involved, fast reaction process, and low preheating temperature [17][18][19]. However, the solution combustion method often results in the shortcoming of a low specific surface area as well as large particle size, which will decrease the catalyst activity.…”