Provided in this disclosure, in part, are methods, compositions, and systems for degrading organic matter, such as kerogen, in a subterranean formation. Further, these methods, compositions, and systems allow for increased hydraulic fracturing efficiencies in subterranean formations, such as unconventional rock reservoirs. Also provided in this disclosure is a method of treating kerogen in a subterranean formation including placing in the subterranean formation a composition that includes a first oxidizer including a persulfate and a second oxidizer including a bromate.