The first example that we know of is the arc "The Invisible Empire" from Federal Men by Jerry Siegel and Joe Shuster in New Comics #8-10 (1936).
http://brad-ricca.com/history-proves-again-and-again-siegel-and-shusters-atlantic-rim/https://ultraboy8888.wordpress.com/2014/08/09/new-comics-9-federal-men/http://fourcolorshadows.blogspot.com.br/2011/11/federal-men-siegel-and-shuster-1936.htmlhttp://dccomicsartists.com/superart/JOE_SHUSTER2.htmhttp://mikegrost.com/federal.htmThe brazilian comic strip Audaz, o demolidor by Messias de Mello debuted in A Gazetinha #445 (December 17, 1938).
The brazilian comic strip Audaz, o demolidor by Aruom (scripts) and Messias de Mello (art) debuted in A Gazetinha #445 (December 17, 1938), in this issue, Superman made debut in the country. The first arc was published until 1940.
Between 1948 and 1949, another arc by Lindbergh (script) and Messias de Mello (art) was published in the same supplement.
http://artistamessiasdemello.blogspot.com.br/https://www.flickr.com/photos/messiasmello/http://www.messiasdemello.com.br/according to Overstreet's Comic Book Price Guide, Bozo the Iron Man was the first robot to appear in a comic book cover, but, however, not he, before he and the Audaz. In fact, the first robot in a magazine cover was a robot created by Herg