Mohammed Abbkr, 28, from Edgbaston in Birmingham, is alleged to have sprayed a substance on to the two Muslim victims in the separate incidents.
At Birmingham Magistrates' Court, Mr Abbkr, who is originally from Sudan, spoke only to confirm his name, age and address and was remanded in custody.
He is due at a Crown court on 20 April.
Hashi Odowa, 82, was set alight by a mosque in Ealing, west London, on 27 February.
Mohammed Rayaz, 70, was also set on fire and seriously injured in Edgbaston, Birmingham, on Monday.