Controlling chemical reactions is a key goal in chemistry. Over the past century, numerous studies have demonstrated that chemical reactions can be altered by modifying molecular structures, adding catalysts, or applying external fields. With the development of quantum mechanics, scientists have established the fundamental principles of modern chemistry, understood the underlying mechanisms of chemical reactions, and exploited quantum mechanical effects to master chemical reactions. In general, quantum-electrodynamic (QED) effects are considered small enough to be neglected in chemical reactions, although Richard Feynman once stated that 'the theory behind chemistry is quantum electrodynamics'. Recently, several experiments demonstrated that QED effects can significantly affect chemical reactions under vibrational strong coupling, which goes beyond the scope of traditional chemistry, providing new insights into fundamental science and promoting the development of cavity chemistry (polariton chemistry). However, to achieve vibrational strong coupling, specific dielectric environments are required, such as optical cavities or plasmonic cavities, leading to the difficulty of realizing cavity-modified chemical reactions. Motivated by the recent development of cavity chemistry, we questioned whether it is possible to harness QED effects to control chemical reactions in the absence of cavities. Furthermore, if cavity-free QED effects can be employed to influence chemical reactions, what are their mechanisms and are there new fundamental principles in chemistry?