A chemical reactor, comprising: a) an ionic liquid, supported on a porous solid; and b) a Brønsted acid; wherein the ionic liquid serves as an adsorbent and promoter for the Brønsted acid, and the Brønsted acid is a catalyst for alkylation, oligomerization, or a combination thereof of a hydrocarbon mixture comprising at least one alkylatable hydrocarbon and at least one alkylating agent in the chemical reactor. Also, a chemical reactor, comprising: a) a gaseous HCl, which is a catalyst for oligomerization of olefins; b) a chloroaluminate ionic liquid, supported on a porous solid, wherein the chloroaluminate ionic liquid serves as an adsorbent and promoter for the catalyst; and c) a volatile hydrocarbon, which evaporates to control a heat of reaction in the chemical reactor.