Carbonic anhydrases (CA-s) are an attractive type of catalyst for CO₂ capture system, offering a high hydration and dehydration activity for CO₂. However, reduced enzyme stability limits the industrial application of CA-s. Bovine erythrocyte CA (bCA) is one of the most active variants of CA because of its high enzyme activity and commercial scale production, but the lifetime at elevated temperature is limited because of its mesophilic nature. This led us to explore the hypothesis that adsorption-induced thermal stabilization would enhance the properties of bCA. A thermally stable zeolitic imidazole framework (ZIF) with large pores ZIF-90 was chosen, and bCA was encapsulated withing the ZIF-90 crystals (bCA@ZIF-90) via a water-based synthesis. The as-synthesized bCA@ZIF-90 was characterized by X-ray diffraction (XRD), N₂ adsorption, scanning electron microscopy (SEM), and infrared (IR) and Raman spectroscopy and the data was compared with that of regular ZIF-90. The catalytic hydration and dehydration activity of CO₂ by bCA@ZIF-90 was studied using a stopped-flow technique using UV-vis absorption spectrometry and colorimetric responses of pH-sensitive dyes. The concentration of bCA@ZIF-90 was intentionally kept low to reduce interference with the UV-vis absorption of the dyes. This resulted in an effective bCA concentration of 65 ± 3 nM  (1.95 ± 0.09 μg bCA/mL), up to three orders of magnitude lower than that reported in previous literature. The thermal stability of bCA@ZIF-90 was evaluated by incubation at pH 9.4 and 7.1 at 60°C for three weeks. ZIF-90 itself was incubated at pH 9.4 and 7.1 at 60°C for two weeks, and boiled at pH 7.1 for 24 h. The enzyme-containing bCA@ZIF-90 exhibited a well resolved diffractogram consistent with as-synthesized and simulated ZIF-90 structure, indicating that crystallinity was preserved during introduction of bCA. BET analysis of the N₂ adsorption of the regular ZIF-90 sample revealed a surface area of 890 m²/g, and the N₂ adsorption/desorption traces exhibited a hysteresis loop in the region of p/p⁰ = 0.3–0.4, which we ascribed to interparticle mesopores with a Barrett-Joyner-Halenda (BJH) analysis of the desorption branch. We hypothesize that the bCA in bCA@ZIF-90 resides in these crystal defects. IR spectral analyzes revealed bands consistent with amide I and amide II modes of the CA polypeptide backbone in bCA@ZIF-90. Analyzes of the reaction kinetics showed that bCA@ZIF-90 catalyzed the hydration of CO₂ at pH 9.4 and 7.1 at temperatures 30–60°C, and that hydration kinetics was enhanced by a factor 1.2 ± 0.1 (95% CI [1.17, 1.23]) at pH 9.4 and 2.1 ± 0.6 (95% CI [1.9, 2.3]) at pH 7.1 when using bCA@ZIF-90 compared to the uncatalyzed reaction. As the effective enzyme concentration was kept very low, only moderate rate enhancements were observed. Dehydration by bCA@ZIF-90 exhibited a more complicated behavior, where catalytic effects were observed at temperatures T ≥ 40°C.  In relation to thermal stability, enzyme activity of bCA@ZIF-90 was maintained after incubation for 3 weeks at 60°C. However, the XRD patterns of incubated samples of ZIF-90 revealed that it had transformed into another crystalline compound with a large unit cell when incubated at 60°C. The XRD pattern of ZIF-90 boiled at 100°C pH 7.1 for 24 h was consistent with a full recrystallization into a compound with likely a smaller unit cell. The phase-transformation of ZIF-90 also appeared to be pH-dependent, and it is concluded that bCA is stabilized by the adsorption and that more stable porous materials than ZIF-90 could be explored.