In most of the place, it is given that less electropositive metal sulfides can be self-reduced eg. Cu, Pb, Hg etc. But I didn't find out any reason why least electropositive metals like Ag and Au can't be self-reduced?
S or Au2
S can't be self-reduced?
I am not able to find out any single source which suggests that Au or Ag can be extracted via auto reduction method. Even the Reduction potential of Ag+
is +0.7996 V and Reduction potential of Cu2+
is +0.337 V.
P.S. I found out only this paper, otherwise, there is no mention in the literature.https://link.springer.com/article/10.1007/s10973-012-2300-z