Would it be OK to say "我要更努力地学中文”？
我会 would be like making a promise to the speaker.
我要 would be like making a promise to yourself.
In some places 学习 gets translated as learn and others as study. The same with 学. That is a bit confusing and frustrating.
This is due to the flow of the sentence, the "rules", if you could call it that, is to ensure the sentence sounds smooth, which comes with more exposure to the language (practice reading, listening, etc).