Majma al-Zawaid 1428 — How many prayers may be performed with one

Sayyiduna Abdullah bin Abbas (may Allah be pleased with them both) said: It is the Sunnah that a man performs only one prayer with dry ablution (tayammum), and then performs dry ablution again for the next prayer.
Al-Tabarani recorded it in al-Mu'jam al-Kabir; its chain contains al-Hasan bin Imarah, whom Shu'bah, Sufyan and Ahmad bin Hanbal declared "da'if" (weak).