Pyrolysis temperature tunes the catalytic properties of CuBTC-derived carbon-embedded copper catalysts for partial hydrogenation

Abstract

A family of carbon-embedded copper catalysts was synthesized by pyrolyzing copper benzene-1,3,5-tricarboxylate (Cu-BTC) at various temperatures ranging from 400 to 900 degrees C. Characterization of catalysts demonstrated that the density of defect sites on the carbon support increases with an increase in the pyrolysis temperature leading to an increase in the electron density on the copper sites. Catalytic performance tests on 1,3-butadiene hydrogenation showed that the performance becomes more stable as the pyrolysis temperature increases above 800 degrees C such that the catalyst prepared by pyrolysis at 900 degrees C provided a stable performance for more than 12 h, while the one prepared at 400 degrees C was deactivating by >25%. Data further demonstrated a strong dependence of the turnover frequencies to the defect site density on the carbonaceous layer. These results present a versatile approach for preparing carbon-embedded copper catalysts with tunable electronic structure and consequent catalytic properties.