You can create the procedure below in you master database and run this procedure from the database to which you want to grant permissions. Also, the default role name is Execute_StoredProcedure. You can pass in the role name as a parameter

/*     

This procedure grants Execute permissions to all procedures on a database to the role desired.     

The default role is Execute_storedprocedure     

*/     

CREATE procedure sp_grant_permissions_proc @role varchar(100)='Execute_StoredProcedure' as     

declare curname cursor for select name,user_name(uid) from sysobjects where xtype = 'P'     

declare @procname varchar(100)     

declare @username varchar(100)     

open curname     

fetch next from curname into @procname, @username     

while @@fetch_status = 0     

begin     

declare @sql varchar(300)     

set @sql = 'grant execute on ' + @username + '.[' + @procname + '] to ' + @role 

exec(@sql)     

fetch next from curname into @procname, @username     

end     

close curname     

deallocate curname