Does the aforementioned supplication contain anything impermissible?

All praise is due to Allah.

There is nothing objectionable in this form of supplication, as its phrases are correct in meaning. There is no harm in supplicating with it, or using some of its phrases to appeal to Allah, or praising Him with them, even if no specific text has been transmitted concerning it.

However, this form should not be taken as a fixed litany that people are invited to recite. Rather, people should be invited to the legitimate litanies established from the Prophet, peace and blessings be upon him, based on the statement of Sheikh al-Islam Ibn Taymiyyah: "Acts of worship are based on divine command and adherence [to tradition], not on whims and innovation."

It is better for a Muslim to adhere to the forms of remembrance (dhikr) found in the Quran and Sunnah (definition), in order to be rewarded for the remembrance and for the adherence. And Allah knows best.