Cutting elements including polycrystalline diamond compacts for earth-boring tools

A method of forming a polycrystalline diamond compact cutting element for an earth-boring tool, comprising:

• forming a diamond table comprising a polycrystalline diamond material and a first catalyst material disposed in interstitial spaces between inter-bonded diamond crystals of the polycrystalline diamond material;
• at least substantially removing the first catalyst material from the interstitial spaces in the polycrystalline diamond material in at least a portion of the diamond table, the at least a portion of the diamond table including a peripheral portion of the diamond table extending laterally inwardly from a sidewall thereof and longitudinally spaced from a cutting face thereof;
• and
• introducing a second material formulated to promote a higher rate of degradation of the diamond material responsive to exposure to an elevated temperature than a rate of degradation of the diamond material having the first catalyst material at least substantially removed from the interstitial spaces under a substantially equivalent elevated temperature into the interstitial spaces between the inter-bonded diamond crystals only in at least a segment of the peripheral portion of the diamond table adjacent the sidewall and longitudinally spaced from the cutting face.