Imam cannot supplicate only for himself during prayer
1 hadith
Hadith 1073
ولا يوم قوما فيخص نفسه بدعوة دونهم فان فعل فقد خانهم
"It is not permissible for a person to lead people in prayer and then supplicate only for himself, leaving out others; if he does so, he has certainly betrayed the people."