を中心に・をもとに: the difference
を中心にN2
Meaning
Focused on, Centered on or around, Mainly, Most notably
Past papers
Tested 4 times in past papers
Example
てるはしさんを中心に世界が回っている。
The world revolves mainly around Teruhashi-san.
をもとにN2
Meaning
Based on, From, According to
Past papers
Example
これは祖母のレシピをもとに作ったうどんです。
This udon is made from my grandmother's recipe.
How to tell them apart
「を中心に」: who or what is the core, where the focus is.
「をもとに」: the material or original that you base something on: 「小説をもとに映画を作る」 (make a film based on a novel).