Historically, clay-based catalysts played a pivotal role in the
processing of crude oil in the 1930s–1960s (Kimberlin, 1957) and
have ignited a new round of extensive interest in the late 1970s in
larger porous materials for possible catalysts for fluid catalytic
cracking (FCC) of heavy oil (Johnson et al., 1988). Meanwhile, many
researchers have been attempting to use them as catalysts in the
green synthesis of fine chemicals and the removal of pollutants by
their peculiar adsorptive capacity and catalysis. In many cases, several
such strategies as acidification, pillaring, and supporting are combined
to make catalysts for these purposes. For example, in this issue,
Bineesh et al. suggest that selective catalytic oxidation of H2S