Liquid acids as homogeneous catalysts have been playing a major role in chemical-related processes, however simultaneously accompanied by the difficulty of separation and recovery, unfavorable conditions of reactor corrosion and waste acid treatment. In this sense, the exploration of alternative acid catalysts to meet the requirement of current chemical process is of great importance. Comparatively speaking, magnetic solid acids, combined with both properties of acceptable acidity and easy separation from reaction systems, are a new kind of promising heterogeneous catalyst and have being received more and more research interest. Within the context, the recent research advance in the various preparation methods towards magnetic solid acids, effectiveness of different synthesis pathways and the catalytic applications of magnetic solid acids in corresponding reactions are summarized. Meanwhile, the existing problems and the direction of future development of magnetic solid acids have also been outlined in this review. Contents
1 Introduction
2 Preparation and application of magnetic solid acids
2.1 Preparation and catalytic application of magnetic nanoparticles
2.2 Post-synthetic protocol
2.3 Co-condensation method
2.4 Other pathways toward magnetic solid acids
3 Conclusion and outlook