I'm having this same argument at the moment on a Catholic forumhttp://forums.catholic.com/showthread.php?t=114695
From the Catechism...
881: The Lord made Simon alone, whom he named Peter, the "rock" of his Church. He gave him the keys of his Church and instituted him shepherd of the whole flock. "The office of binding and loosing which was given to Peter was also assigned to the college of apostles united to its head." This pastoral office of Peter and the other apostles belongs to the Church's very foundation and is continued by the bishops under the primacy of the Pope.http://www.scborromeo.org/ccc/para/881.htm
The Catholic argument is that the Bible mentions keys specifically only in relation to Peter.
Matthew 16:13 When Jesus came to the region of Caesarea Philippi, he asked his disciples, "Who do people say the Son of Man is?"
14 They replied, "Some say John the Baptist; others say Elijah; and still others, Jeremiah or one of the prophets."
15 "But what about you?" he asked. "Who do you say I am?"
16 Simon Peter answered, "You are the Christ, the Son of the living God."
17Jesus replied, "Blessed are you, Simon son of Jonah, for this was not revealed to you by man, but by my Father in heaven.
18 And I tell you that you are Peter, and on this rock I will build my church, and the gates of Hades will not overcome it.
19 I will give you the keys of the kingdom of heaven; whatever you bind on earth will be bound in heaven, and whatever you loose on earth will be loosed in heaven."
20 Then he warned his disciples not to tell anyone that he was the Christ.
However not long after this Jesus gives the rest of the Apostles the rights to bind and loose. Matthew 18:18 "I tell you the truth, whatever you bind on earth will be bound in heaven, and whatever you loose on earth will be loosed in heaven.
No doubt Peter had the keys. But did he have them 'alone'? How one gets to 'bind and loose' without the keys is interesting. Some Church Fathers recognise that the other Apostles also got the keys
Hilary of Poitiers is quite clear that all who hold that faith have the keys for binding and loosing...
37. This faith it is which is the foundation of the Church; through this faith the gates of hell cannot prevail against her. This is the faith which has the keys of the kingdom of heaven. Whatsoever this faith shall have loosed or bound on earth shall be loosed or bound in heaven. This faith is the Father's gift by revelation; even the knowledge that we must not imagine a false Christ, a creature made out of nothing, but must confess Him the Son of God, truly possessed of the Divine nature
Hilary of Poitiers "On the Trinity" Book VI.http://www.ccel.org/fathers2/NPNF2-09/Npnf2-09-13.htm#P1388_859877
Ã¢â‚¬ÂFor the Son of thunder *, the beloved of Christ, the pillar of the Churches throughout the world, who holds the keys of heaven, who drank the cup of Christ, and was baptized with His baptism, who lay upon his MasterÃ¢â‚¬â„¢s bosom, with much confidence, this man now comes forward to us nowÃ¢â‚¬Â John Chrysostom, Ã¢â‚¬Å“Homilies on the Gospel of John, Homily 1.1Ã¢â‚¬Â
quoted in Schaff, P, Ã¢â‚¬Å“Nicene and Post-Nicene FathersÃ¢â‚¬Â (Grand Rapids: Eerdmans, 1956), Volume XIV, p1 Also at: http://www.ccel.org/fathers2/NPNF1-14/npnf1-14-05.htm#P175_1913
*that is the Apostle John
Commentaries on the Gospel of Matthew: Book XII. "The Promise Given to Peter Not Restricted to Him, But Applicable to All Disciples Like Him."http://www.ccel.org/fathers2/ANF-10/anf10-48.htm