Using SFML on an emulator would be tons of work since it would require that the generated binary complies to the SNES system. Consoles like that have very specific hardware with specific parts for rendering, audio, and also the CPU is an "exotic system" in that regard. So using OpenGL based rendering is completely out of the question unless someone has implemented some kind of OpenGL implementation for SNES which i highly doubt.
And SFML uses OpenGL for rendering. The same goes for audio and just about anything that SFML implements that would need system specific implementations.
Aside from that, you'd also need to find a compiler suite which is capable of taking C++ code and output the binary format that the SNES uses, and also package all of it with all data assets in the proper ROM format.
Theoretically, with a _lot_ of rewriting SFML using heaps of knowledge about the SNES hardware/format, and probably a lot of custom tools, then maybe it is possible. But in practice, no, not in any way that I know of.