No, there's no reason for us to pray for the devil to have a change of heart and be converted. The Bible makes it clear that Satan's doom is certain, and that someday he will be cast "into the eternal fire prepared for the devil and his angels" (Matthew 25:41).
Never forget that Satan is absolutely opposed to God, and he always will be. This has been true since the beginning of time, when he rebelled against God and tried to take over God's position as Lord of the universe. All evil comes from him, and he will do everything he can to spew forth deception and death upon the earth. The Bible says that "there is no truth in him. When he lies, he speaks his native language, for he is a liar and the father of lies" (John 8:44).
No, we don't pray for Satan to repent but the Bible does tell us to pray that he will be bound, and that those who follow him will be blocked from carrying out their evil schemes. We should pray this both for ourselves and our world. The Apostle Paul wrote, "Pray that we may be delivered from wicked and evil men, for not everyone has faith" (2 Thessalonians 3:2).
The most important truth about Satan, however, is that he is a defeated foe, for by His death and resurrection Jesus Christ conquered Satan. Is your faith and trust in Christ?