In 2003, a group of researchers published results on high-temperature superconductivity in palladium hydride (PdHx: x>1)[REF] and an explanation in 2004 [REF].
In 2015, an article published in Nature by researchers of the Max Planck Institute suggested that under certain conditions such as extreme pressure H2S transitioned to a superconductive form H3S at around 1.5 million times atmospheric pressure in a diamond anvil cell.