Hierarchical FAU-type zeolite nanosheets as green and sustainable catalysts for benzylation of toluene Thittaya Yutthalekha a, b, c , Chularat Wattanakit a , Chompunuch Warakulwit b, c , Wannaruedee Wannapakdee a , Kamonlatth Rodponthukwaji b, c , Thongthai Witoon c, d , Jumras Limtrakul e, * a Department of Chemical and Biomolecular Engineering, School of Energy Science and Engineering, Vidyasirimedhi Institute of Science and Technology, Rayong 21210, Thailand b Department of Chemistry and NANOTEC Center for Nanoscale Materials Design for Green Nanotechnology, Faculty of Science, Kasetsart University, Bangkok 10900, Thailand c Center for Advanced Studies in Nanotechnology and Its Applications in Chemical, Food and Agricultural Industries, Kasetsart University, Bangkok 10900, Thailand d Department of Chemical Engineering, Faculty of Engineering, Kasetsart University, Bangkok 10900, Thailand e Department of Materials Science and Engineering, School of Molecular Science and Engineering, Vidyasirimedhi Institute of Science and Technology, Rayong 21210, Thailand article info Article history: Received 28 December 2015 Received in revised form 8 July 2016 Accepted 1 August 2016 Available online 3 August 2016 Keywords: Green catalyst Hierarchical zeolite Organosilane Clean benzylation Recyclable synthesized precursor abstract The development of recyclable solid acids is of major industrial importance and challenging in many reactions, for instance, the Friedel-Crafts alkylation as one of the most prevalent examples, which generally requires the presence of acid catalysts. However, not only the replacement of traditional toxic acid catalyst by solid acidic zeolites but also the improvement such catalysts in term of high efficiency has been addressed through environmental technologies. Our present study explores the use of hier- archical faujasite zeolite nanosheets as catalysts in industrial applications with the frame of development of green and sustainable technologies. The simple and efficient route to prepare the faujasite zeolite with the nanosheet-assembled structure together with the roles of synthetic parameters on the characteristics and properties are systematically investigated. This first example of hierarchical zeolite, which has uniform mesoporous features derived from the interstitial pores between the nanosheet assemblies, exhibits a superior catalytic activity in terms of conversion and selectivity for the benzylation of toluene with benzyl chloride. In conclusion, the fine-tuning of structural characteristics of zeolites by a simple optimization of surfactant contents and crystallization temperatures allows the design of the candidate catalyst for a green and sustainable future. This work also demonstrates the next step forward in the development of an industrial catalyst based on the concept of cleaner production. © 2016 Elsevier Ltd. All rights reserved. 1. Introduction Currently, many chemical processes have suffered from high- energy consumption, large amount of wastes and pollution. Therefore, sustainable innovation with energy saving, green pro- cesses, and environmental concerns is a desired goal for the chemical industry (Díaz L opez and Montalvo, 2015). The develop- ment of existing industrial catalysts with the intention of increasing their performances in order to efficiently use natural resources, including raw materials, energy and water, while reducing the generation of waste is one of the major goals of the cleaner pro- duction concepts (Glavi c and Lukman, 2007; Jegatheesan et al., 2009). This is portrayed in the new patterns of industrial produc- tion, which is gaining widespread and increasing interest from national society (Zeng et al., 2010). The use of an environmentally friendly chemical process is currently gaining popularity because the use of conventional Lewis and mineral acid catalysts (e.g., AlCl 3 , HF, H 2 SO 4 ) has led to envi- ronmental problems, especially in large-scale production. Great efforts have been made to replace such conventional catalysts with solid acid catalysts. Among them, zeolites have attracted increasing * Corresponding author. E-mail address: jumras.limtrakul@vistec.ac.th (J. Limtrakul). Contents lists available at ScienceDirect Journal of Cleaner Production journal homepage: www.elsevier.com/locate/jclepro http://dx.doi.org/10.1016/j.jclepro.2016.08.001 0959-6526/© 2016 Elsevier Ltd. All rights reserved. Journal of Cleaner Production 142 (2017) 1244e1251