Insights into the electronic modulation of bimetallic Pt-Sn cluster for the selective hydrogenation of 1,3-butadiene

The elucidation of the intrinsic working principle of the electronic property of Pt catalysts for the selective hydrogenation of 1,3-butadiene in the presence of CO remains a substantial challenge. We solve this problem through the synthesis of a series of bimetallic Pt-Sn clusters encapsulated in the zeolite channel, followed by manipulation of the Pt-Sn composition to further tuning the electronic property of Pt. By excluding the possible interference from Pt cluster size and distribution, we were able to evaluate the solely intrinsic influence of the electronic property of Pt on the catalytic performance. In the presence of CO, a volcano correlation between the catalytic reactivity and the increased Sn/Pt input ratio has been clearly established. Among the prepared catalysts, PtSn3/S-1 exhibits optimal reactivity for the selective hydrogenation of 1,3-butadiene to butene with a selectivity of 92% and a turnover frequency of 0.41 s(-1). According to our thorough electronic characterization and analyses, competitive CO adsorption on the electronic deficient Pt sites due to the electron withdrawing by Sn has been weakened, and thereby the hydrogenation reactivity is recovered. We anticipate that this study enriches current knowledge for the design of more practical selective hydrogenation Pt catalysts compatible with gas stream containing residual amounts of CO.