Quantifying active sites under reaction conditions is paramount to quantification of per-site turnover frequencies and consequently to direct comparisons of the reactivity of heterogeneous catalysts. In this talk, I will give discuss our efforts to determine the functions of, and quantify, multiple types of active sites present on metal-containing dealuminated Beta (deAlBeta) catalysts. These materials are useful for production of C3+ olefins from ethanol in a single reactor en route to production of sustainable aviation fuel, in a distinct pathway from commercial processes that first dehydrate ethanol to ethylene, then dimerize ethylene to butene in a second reactor. This reaction occurs over multifunctional copper-, zinc-, and yttrium-containing deAlBeta zeolites, via a series pathway requiring dehydrogenation, aldol condensation, hydrogenation, and dehydrations in a precise sequence. Product formation rates in these trimetallic catalysts are proportional to the density of Lewis acidic yttrium sites, motivating studies of monometallic Y/deAlBeta catalysts. We have quantified the number of Lewis acidic active sites in these materials via ex situ and in situ chemical titrations, and determined that there is evidence for at least two types of yttrium sites that collectively catalyze dehydration, aldol condensation, and Meerwein-Pondorff-Verley (MPV) reduction. Y-containing sites that form crotonaldehyde and crotyl alcohol are distinct from those that catalyze crotyl alcohol dehydration, based on in situ titration experiments and the deactivation profiles for each product with time on stream. By varying residence time, we evince that crotonaldehyde and crotyl alcohol are intermediates enroute to butadiene formation. Isotopic tracer studies on Y/deAlBeta and La/deAlBeta suggest ethanol to acetaldehyde conversion via coupled MPV reduction and Oppenaeur oxidation (MPVO) reactions occur in addition to crotonaldehyde to crotyl alcohol MPV reduction, and that ethanol-acetaldehyde interconversion is quasi-equilibrated. The kinetics and product selectivities during reaction of ethanol-acetaldehyde mixtures over monometallic yttrium- or lanthanum-containing deAlBeta zeolite catalysts are disparate, suggesting predictable differences in these metals as primary binding sites for adsorption and conversion of small oxygenates. These findings aid in our ongoing efforts to reduce the cost and carbon footprint of SAF production.