Every committed Muslim is required by Allah to make Du`aa and implore Him earnestly. Referring to this, Allah Almighty says, “And your Lord hath said: Pray unto me and I will hear your prayer. Lo! those who scorn My service, they will enter hell, disgraced.” (Ghafir: 60)
Dr.`Ugail Jasem An-Nashmi, professor of Shari`ah and former deputy chairman of the Kuwaiti Fatwa Committee, states the following: “During prayer, it is preferable to make Du`aa when prostrating and after reciting the last Tashahud. It is part of the Sunnah to recite the Du`aa using Qur’anic verses that contain supplications. If there is a Prophetic Hadith that contains a certain Du`aa formula, then it is not necessary to recite the exact words mentioned in the Hadith when reciting the Du`aa. There is nothing wrong in using words other than those mentioned in the Hadith.
Muslim jurists have disagreed regarding the point you have raised concerning making Du`aa for worldly benefits in prayer.
Both Malikies and Shafi`’ies maintain that there is nothing wrong with making such Du`aa in prayer as long as one avoids making supplications to achieve something Haram.
On the other hand, the Hanbalis maintain that it is not permissible to make such Du`aa in prayer. The opinion, which is deemed to be the most correct is the one maintained by both Malikies and Shafi`’ies as there is no specific evidence to
prohibit it.”
It has become clear now that there is nothing wrong, as far as Islam is concerned, that one makes Du`aa for things of this world as long as one does not implore Allah to achieve something Haram.