RESEARCH PAPER Green preparation of Pd nanoparticles on SBA-15 via supercritical fluid deposition and application on Suzuki–Miyaura cross-coupling reaction Fatma Ulusal & Ebru Erünal & Bilgehan Güzel Received: 5 April 2018 /Accepted: 9 August 2018 # Springer Nature B.V. 2018 Abstract A well-dispersed green Pd/SBA-15 catalyst with an average size of 13.7 nm and 492.6 m 2 /g BET surface area is prepared via supercritical fluid deposition method with a new bipyridyl precursor that enables reduc- tion at mild conditions at 80 °C and 17.2 MPa. The catalytic performance of Pd/SBA-15 prepared using scCO 2 with hydrogen reduction was assessed for Suzuki –Miyaura coupling reaction of bromobenzene and phenylboronic acid that was chosen as a model coupling reaction. The catalyst was tested in six different solutions and in three organic and inorganic bases during reactions. In general, the effect of bases is investigated when solvents are held constant and K 2 CO 3 appears to have the best results in the activity studies used. For each of the 3 bases used, the highest catalytic activity was reached as the result of the solvent system being ethanol/water (1:1). The highest catalytic conversion was obtained in the ethanol- K 2 CO 3 solvent-base pair. The catalyst synthesized in this study exhibited high activities and TON value was found as 160.8 at room temperature. Keywords SBA-15 . Suzuki–Miyaura cross-coupling reaction . Supercritical deposition . Green chemistry . Palladium nanoparticle Introduction Green methods are more preferred in industrially important reactions due to the environmental con- cerns and thanks to developments in green chemis- try. Especially in organic synthesis, alternative green processes can be eco-friendly and reduce costs (Beckman 2004). In this sense, the use of supercrit- ical solvents instead of conventional organic sol- vents is an effective approach. The most commonly used green solvents for alternative in organic syn- thesis are supercritical carbon dioxide, supercritical, and subcritical water (Gang et al. 2003; Ulusal et al. 2015). Supercritical carbon dioxide (scCO 2 ) offers real potential as an alternative, environmentally be- nign reaction medium for the green preparation of organic molecules because it is nontoxic, cheap, and easily separable from reaction media (Meng et al. 2018; Hiramatsu and Hori 2010). Thanks to these features, it gains importance day by day and is used as an alternative solvent. Especially, supercrit- ical fluids have been used in various techniques such as organic synthesis (Ulusal et al. 2015; Morère et al. 2015a, b), deposition of metals on the solid materials (Meng et al. 2018; Bozbag et al. 2012), extraction, food, cosmetics, pharmaceutics, materials, chemistry, sterilization, cleaning, J Nanopart Res (2018) 20:219 https://doi.org/10.1007/s11051-018-4325-0 F. Ulusal : B. Güzel Chemistry Department, The Faculty of Arts and Sciences, Çukurova University, 01330 Adana, Turkey F. Ulusal (*) Clinical Biochemistry Department, The Faculty of Medicine, Gaziantep University, 27310 Gaziantep, Turkey e-mail: fatma_ulusal@hotmail.com E. Erünal Chemical Engineering Department, The Faculty of Ceyhan Engineering, Çukurova University, 01950 Adana, Turkey